Gas valve with electronic valve proving system

ABSTRACT

A valve assembly may be configured to perform a valve proving test as part of an operational cycle of a combustion appliance coupled to the valve assembly. The valve assembly may include a valve body having a fluid path, first and second valve sealing members translatable between an opened position and a closed position, and one or more pressure sensors in fluid communication with an intermediate volume of the fluid path between the first and second valve sealing members. A valve controller may be in communication with the pressure sensor and may monitor a measure related to a pressure change rate in the intermediate volume. The valve controller may then output a signal if the measure related to a pressure change rate in the intermediate volume meets and/or exceeds a threshold value.

TECHNICAL FIELD

The disclosure relates generally to valves, and more particularly, togas valve assemblies.

BACKGROUND

Valves are commonly used in conjunction with many appliances forregulating the flow of fluid. For example, gas valves are oftenincorporated into gas-fired appliances to regulate the flow of gas to acombustion chamber or burner. Examples of such gas-fired appliances mayinclude, but are not limited to, water heaters, furnaces, boilers,fireplace inserts, stoves, ovens, dryers, grills, deep fryers, or anyother such device where gas control is desired. In such gas-firedappliances, the gas may be ignited by a pilot flame, electronic ignitionsource, or other ignition source, causing combustion of the gas at theburner element producing heat for the appliance. In many cases, inresponse to a control signal from a control device such as a thermostator other controller, the gas valve may be moved between a closedposition, which prevents gas flow, and an open position, which allowsgas flow. In some instances, the gas valve may be a modulating gasvalve, which allows gas to flow at one or more intermediate flow ratesbetween the fully open position and the fully closed position.

SUMMARY

This disclosure relates generally to valves, and more particularly, togas valve assemblies. In one illustrative but non-limiting example, avalve assembly may be configured for controlling fuel flow to acombustion appliance, where the combustion appliance may cycle on andoff during a sequence of operational cycles. The combustion appliancemay, in some cases, also perform one or more valve proving tests duringan operational cycle.

In an illustrative embodiment, the valve assembly may include a valvebody having an inlet port and an outlet port with a fluid path extendingbetween the inlet port and the outlet port. The valve assembly mayinclude a first valve situated in the fluid path between the inlet portand the outlet port, and a second valve situated in the fluid pathbetween the inlet port and the outlet port downstream of the firstvalve, with an intermediate volume defined between the first valve andthe second valve. The valve assembly may include a pressure sensor influid communication with the intermediate volume between the first valveand the second valve. The pressure sensor may be configured to sense ameasure that is related to the pressure in the intermediate volume.

In some instances, a valve controller of the valve assembly may besecured relative to the valve body. The valve controller may be incommunication with the pressure sensor. The valve controller may receivethe measure related to a pressure in the intermediate volume from thepressure sensor, and determine a measure that is related to a pressurechange rate in the intermediate volume during a valve proving test,where the valve proving test may be performed as part of at least one ofthe operational cycles of the combustion appliance.

In some cases, and during a valve proving test, the valve controller mayclose the upstream first valve and open the downstream second valve,which may depressurize the intermediate volume between the first valveand the second valve. The second valve may then be closed to seal thedepressurized intermediate volume. After closing the second valve, thepressure sensor may sense a measure related to the pressure in theintermediate volume, and a first measure that is related to a pressurechange rate in the intermediate volume may be determined. Once the firstmeasure has been determined, the valve controller (or other controller)may compare the first measure to a first pressure threshold value. Thevalve controller (or other controller) may output a first predeterminedsignal if the first measure meets and/or exceeds the first thresholdvalue. This test may help prove that the upstream first valve properlycloses and does not leak beyond a threshold value.

Likewise, during a valve proving test, the valve controller may closethe downstream second valve and open the upstream first valve, which maypressurize the intermediate volume between the first valve and thesecond valve. The first valve may then be closed to seal the pressurizedintermediate volume. After closing the first valve, the pressure sensormay sense a measure related to the pressure in the intermediate volume,and a second measure that is related to a pressure change rate in theintermediate volume may be determined. Once the second measure has beendetermined, the valve controller (or other controller) may compare thesecond measure to a second pressure threshold value. The valvecontroller (or other controller) may output a second predeterminedsignal if the second measure meets and/or exceeds the second thresholdvalue. This test may help prove that the downstream second valveproperly closes and does not leak beyond a threshold value.

The preceding summary is provided to facilitate an understanding of someof the innovative features unique to the present disclosure and is notintended to be a full description. A full appreciation of the disclosurecan be gained by taking the entire specification, claims, drawings, andabstract as a whole.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure may be more completely understood in consideration of thefollowing detailed description of various illustrative embodiments inconnection with the accompanying drawings, in which:

FIG. 1 is a schematic perspective view of an illustrative fluid valveassembly;

FIG. 2 is a schematic first side view of the illustrative fluid valveassembly of FIG. 1;

FIG. 3 is a schematic second side view of the illustrative fluid valveassembly of FIG. 1, where the second side view is from a side oppositethe first side view;

FIG. 4 is a schematic input side view of the illustrative fluid valveassembly of FIG. 1;

FIG. 5 is a schematic output side view of the illustrative fluid valveassembly of FIG. 1;

FIG. 6 is a schematic top view of the illustrative fluid valve assemblyof FIG. 1;

FIG. 7 is a cross-sectional view of the illustrative fluid valveassembly of FIG. 1, taken along line 7-7 of FIG. 4;

FIG. 8 is a cross-sectional view of the illustrative fluid valveassembly of FIG. 1, taken along line 8-8 of FIG. 2;

FIG. 9 is a schematic diagram showing an illustrative fluid valveassembly in communication with a building control system and anappliance control system, where the fluid valve assembly includes adifferential pressure sensor connect to a valve controller;

FIG. 10 is a schematic diagram showing an illustrative fluid valveassembly in communication with a building control system and anappliance control system, where the fluid valve assembly includesmultiple pressure sensors connected to a valve controller;

FIG. 11 is a schematic diagram showing an illustrative schematic of alow gas pressure/high gas pressure limit control;

FIG. 12 is a schematic diagram showing an illustrative schematic valvecontrol and combustion appliance control, where the controls areconnected via a communication link;

FIG. 13 is a schematic diagram showing an illustrative valve control andproof of closure system in conjunction with a combustion appliance; and

FIGS. 14-17 are various illustrative schematic depictions of differentmethods for sensing a position and/or state of a valve within anillustrative valve assembly.

While the disclosure is amenable to various modifications andalternative forms, specifics thereof have been shown by way of examplein the drawings and will be described in detail. It should beunderstood, however, that the intention is not to limit aspects of thedisclosure to the particular illustrative embodiments described. On thecontrary, the intention is to cover all modifications, equivalents, andalternatives falling within the spirit and scope of the disclosure.

DESCRIPTION

The following description should be read with reference to the drawingswherein like reference numerals indicate like elements throughout theseveral views. The detailed description and drawings show severalillustrative embodiments which are meant to be illustrative of theclaimed disclosure.

Gas valves may be added to fluid path systems supplying fuel and/orfluid to appliances (e.g., burners, etc.) or may be used individually orin different systems. In some instances, gas safety shutoff valves maybe utilized as automatic redundant valves. Redundancy is achieved, andoften times required by regulatory agencies, by placing at least twosafety shutoff valves in series. The aforementioned redundant valves maybe separate valves fitted together in the field and/or valves locatedtogether in a single valve body, these redundant valves are commonlyreferred to as double-block valves. In accordance with this disclosure,these and other gas valves may be fitted to include sensors and/orswitches and/or other mechanical or electronic devices to assist inmonitoring and/or analyzing the operation of the gas valve and/orconnected appliance. The sensors and/or switches may be of theelectromechanical type or the electronic type, or of other types ofsensors and/or switches, as desired.

In some cases, a gas valve assembly may be configured to monitor and/orcontrol various operations including, but not limited to, monitoringfluid flow and/or fluid consumption, electronic cycle counting,overpressure diagnostics, high gas pressure and low gas pressuredetection, valve proving system tests, valve leakage tests, proof ofvalve closure tests, diagnostic communications, and/or any othersuitable operation as desired.

Valve Assembly

FIG. 1 is a schematic perspective view of an illustrative fluid (e.g.,gas, liquid, etc.) valve assembly 10 for controlling fluid flow to acombustion appliance or other similar or different device. In theillustrative embodiment, the gas valve assembly 10 may include a valvebody 12, which may generally be a six sided shape or may take on anyother shape as desired, and may be formed as a single body or may bemultiple pieces connected together. As shown, valve body 12 may be asix-sided shape having a first end 12 a, a second end 12 b, a top 12 c,a bottom 12 d, a back 12 e and a front 12 f, as depicted in the variousviews of FIGS. 1-6. The terms top, bottom, back, front, left, and rightare relative terms used merely to aid in discussing the drawings, andare not meant to be limiting in any manner.

The illustrative valve body 12 includes an inlet port 14, an outlet port16 and a fluid path or fluid channel 18 extending between inlet port 14and outlet port 16. Further, valve body 12 may include one or more gasvalve ports 20 (e.g., a first valve port 20 a and a second valve port 20b, shown in FIGS. 7 and 8) positioned or situated in fluid channel 18,one or more fuel or gas valve member(s) sometimes referred to as valvesealing member(s) 22 moveable within gas valve ports 20 (e.g., a firstvalve sealing member 22 a within first valve port 20 a and a secondvalve sealing member 22 b within second valve port 20 b, as shown inFIG. 7), one or more pressure sensor assemblies 24 (as shown in FIG. 8,for example), one or more position sensors 48, and/or one or more valvecontrollers 26 (as shown in FIG. 8, for example) affixed relative to orcoupled to valve body 12 and/or in electrical communication (e.g.,through a wired or wireless connection) with pressure sensor assemblies24 and position sensor(s) 48.

Valve assembly 10 may further include one or more actuators foroperating moving parts therein. For example, valve assembly 10 may haveactuators including, but not limited to, one or more stepper motors 94(shown as extending downward from bottom 12 d of valve body 12 in FIG.1), one or more solenoids 96 (shown as extending upward from top 12 c ofvalve body 12 in FIG. 1), and one or more servo valves 98 (a servo valve98 is shown as extending upward from top 12 c of valve body 12 in FIG.1-3, where a second servo valve has been omitted), where servo valve 98may be a 3-way auto-servo valve or may be any other type of servo valve.In one illustrative embodiment, the one or more solenoids 96 controlwhether the one or more gas valve ports 20 are open or closed. The oneor more stepper motors 94 determine the opening size of the gas valveports 20 when the corresponding gas valve sealing member 22 is opened bythe corresponding solenoid 96. Of course, the one or more stepper motors94 would not be provided when, for example, the valve assembly 10 is nota “modulating” valve that allows more than one selectable flow rate toflow through the valve when the valve is open.

As shown, valve body 12 may include one or more sensor and electronicscompartments 56, which in the illustrative embodiment, extend from backside 12 e as depicted in FIGS. 1, 2 and 4-6. Sensor and electronicscompartments 56 may be coupled to or may be formed integrally with valvebody 12, and may enclose and/or contain at least a portion of valvecontrollers 26, pressure sensors assemblies 24 and/or electronicsrequired for operation of valve assembly 10 as described herein.Although compartments 56 may be illustratively depicted as separatestructures, compartments 56 may be a single structure part of, extendingfrom, and/or coupled to valve body 12.

In the illustrative embodiment, the one or more fluid valve ports 20 mayinclude first gas valve port 20 a and second gas valve port 20 bsituated along and/or in communication with fluid channel 18. This is adouble-block valve design. Within each gas valve port 20, a gas valvesealing member 22 may be situated in fluid channel 18 and may bepositioned (e.g., concentrically or otherwise) about an axis, rotatableabout the axis, longitudinally and axially translatable, rotationallytranslatable, and/or otherwise selectively movable between a firstposition (e.g., an open or closed position) and a second position (e.g.,a closed or open position) within the corresponding valve port 20.Movement of the valve sealing member 22 may open and close valve port20.

It is contemplated that valve sealing member 22 may include one or moreof a valve disk 91, a valve stem 92 and/or valve seal 93 for sealingagainst a valve seat 32 situated in fluid channel 18, as best seen inFIGS. 14-17, and/or other similar or dissimilar components facilitatinga seal. Alternatively, or in addition, valve sealing member 22 mayinclude structural features and/or components of a gate valve, adisk-on-seat valve, a ball valve, a butterfly valve and/or any othertype of valve configured to operate from a closed position to an openposition and back to a closed position. An open position of a valvesealing member 22 may be any position that allows fluid to flow throughthe respective gas valve port 20 in which the valve sealing member 22 issituated, and a closed position may be when valve sealing member 22forms at least a partial seal at the respective valve port 20, such asshown in FIG. 7. Valve sealing member 22 may be operated through anytechnique. For example, valve sealing member 22 may be operated throughutilizing a spring 31, an actuator 30 to effect movement against thespring 31, and in some cases a position sensor 48 to sense a position ofthe valve sealing member 22.

Valve actuator(s) 30 may be any type of actuator configured to operatevalve sealing member 22 by actuating valve sealing member 22 from theclosed position to an open position and then back to the closed positionduring each of a plurality of operation cycles during a lifetime of thegas valve assembly 10 or of actuator 30. In some cases, valve actuator30 may be a solenoid actuator (e.g., a first valve actuator 30 a and asecond valve actuator 30 b, as seen in FIG. 7), a hydraulic actuator,magnetic actuators, electric motors, pneumatic actuators, and/or othersimilar or different types of actuators, as desired. In the exampleshown, valve actuators 30 a, 30 b may be configured to selectively movevalves or valve sealing members 22 a, 22 b of valve ports 20 a, 20 bbetween a closed position, which closes the fluid channel 18 betweeninlet port 14 and the outlet port 16 of valve body 12, and an openposition. The gas valve assembly of FIGS. 1-8 is an example of a gassafety shutoff valve, or double-block valve. In some cases, however, itis contemplated that the gas valve assembly 10 may have a single valvesealing member 22 a, or three or more valve sealing members 22 in seriesor parallel, as desired.

In some cases, valve assembly 10 may include a characterized portdefined between inlet port 14 and outlet port 16. A characterized portmay be any port (e.g., a fluid valve port 20 or other port orrestriction through which fluid channel 18 may travel) at or acrosswhich an analysis may be performed on a fluid flowing therethrough. Forexample, if a flow resistance of a valve port 20 is known over a rangeof travel of the valve sealing member 22, the one of the one or more gasvalve ports 20 may be considered the characterized port. As such, and insome cases, the characterized port may be a port 20 having valve sealingmember 22 configured to be in an open position and in a closed position.Alternatively, or in addition, a characterized port may not correspondto a gas valve port 20 having valve sealing member 22. Rather, thecharacterized port may be any constriction or feature across which apressure drop may be measured and/or a flow rate may be determined.

In some cases, the characterized port may be characterized at variousflow rates to identify a relationship between a pressure drop across thecharacterized port and the flow rate through the fluid channel 18. Insome cases, the pressure drop may be measured directly with one or morepressure sensors 42, 43, 44, and/or 38. In other cases, the pressuredrop may be inferred from, for example, the current position of thevalve member(s). These are just some examples. In some cases, therelationship may be stored in a memory 37, such as a RAM, ROM, EEPROM,other volatile or non-volatile memory, or any other suitable memory ofthe gas valve assembly 10, but this is not required.

In some cases, gas valve assembly 10 may include a flow module 28 forsensing one or more parameters of a fluid flowing through fluid channel18, and in some cases, determining a measure related to a gas flow rateof the fluid through the fluid channel 18.

In some instances, flow module 28 may include a pressure block orpressure sensor assembly 24, a temperature sensor 34, a valve memberposition sensor 48 and/or a valve controller 26, among other assemblies,sensors and systems for sensing, monitoring and/or analyzing parametersof a fluid flowing through fluid channel 18, such as can be seen inFIGS. 9 and 10.

It is contemplated that flow module 28 may utilize any type of sensor tofacilitate determining a measure related to a flow rate of a fluidthrough fluid channel 18, such a pressure sensor, a flow sensor, a valveposition sensor, and/or any other type of sensor, as desired. In oneexample, the flow module 28, which in some cases may be part of a valvecontroller 26, may be configured to monitor a differential pressureacross a characterized port, and in some cases, a position of one ormore valve sealing members 22 of the gas valve assembly 10. Theinformation from monitoring may be utilized by the flow module 28 todetermine and monitor the flow rate of fluid (liquid or gas) passingthrough the fluid channel 18. For example, the flow module 28 maydetermine a measure that is related to a gas flow rate through the fluidchannel 18 based, at least in part, on the measure that is related tothe pressure drop across the characterized port along with thepre-stored relationship in the memory 37. In some cases, the currentposition of one or more valve sealing members 22 of the gas valveassembly 10 may also be taken into account (e.g. is the valve 30% open,50% open or 75% open).

In some instances, the flow module 28 may be configured to output theflow rate of fluid passing through the fluid channel 18 to a display ora remote device. In some cases, the flow module 28 may maintain acumulative gas flow amount passing through the fluid channel 18 (e.g.over a time period), if desired. The measure related to a gas flow mayinclude, but is not limited to, a measure of fuel consumption by adevice or appliance that is connected to an output port 16 of the gasvalve assembly 10.

It is contemplated that electronic valve controller or valve controlblock 26 (see, FIG. 8-10) may be physically secured or coupled to, orsecured or coupled relative to, valve body 12. Valve controller 26 maybe configured to control and/or monitor a position or state (e.g., anopen position and a closed position) of valve sealing members 22 ofvalve ports 20 and/or to perform other functions and analyses, asdesired. In some cases, valve control block 26 may be configured toclose or open gas valve member(s) or valve sealing member(s) 22 on itsown volition, in response to control signals from other systems (e.g., asystem level or central building control), and/or in response toreceived measures related to sensed pressures upstream, intermediate,and/or downstream of the characterized valve port(s), measures relatedto a sensed differential pressure across the characterized valveport(s), measures related to temperature sensed upstream, intermediate,and/or downstream of the characterized valve port(s), and/or in responseto other measures, as desired.

The memory 37, which in some cases may be part of valve controller 26,may be configured to record data related to sensed pressures, senseddifferential pressures, sensed temperatures, and/or other measures. Thevalve controller 26 may access this data, and in some cases, communicate(e.g., through a wired or wireless communication link 100) the dataand/or analyses of the data to other systems (e.g., a system level orcentral building control) as seen in FIGS. 9 and 10. The memory 37and/or other memory may be programmed and/or developed to containsoftware to affect one or more of the configurations described herein.

In some instances, valve controller 26 may be considered a portion offlow module 28, flow module 28 may be considered part of valvecontroller 26, or the flow module 28 and valve controller 26 may beconsidered separate systems or devices. In some instances, valvecontroller 26 may be coupled relative to valve body 12 and one or moregas valve ports 20, where valve controller 26 may be configured tocontrol a position (e.g., open or closed positions, including variousopen positions) of valve sealing member 22 within valve port 20. In somecases, the valve controller 26 may be coupled to pressure sensorassembly 24, temperature sensor 34, position sensor 48, and/or othersensors and assemblies, as desired.

In the illustrative embodiment of FIG. 8, valve controller 26 may beconfigured to monitor a differential pressure across a characterizedport. In some instances, valve controller 26 may monitor a differentialpressure across fluid valve port 20 and/or monitor a measure related toa pressure upstream of a fluid valve port 20 (e.g., first valve port 20a) and/or a measure related to a pressure downstream of a fluid valveport 20 (e.g., second valve port 20 b). The valve controller 26 may alsobe configured to monitor an axial position of the valve sealing member22 in valve port 20. As a result, valve controller 26 may determine aflow rate of fluid passing through the characterized port, where valvecontroller 26 may determine the flow rate (and sometimes fluidconsumption) based, at least in part, on the monitored differentialpressure and/or monitored upstream and downstream pressures inconjunction with a pre-characterized relationship between the pressuredrop across the characterized port and the flow rate. In some cases, themonitored axial positioning of valve sealing member 22 may also be takeninto account, particularly when the valve sealing member 22 may assumeone or more intermediate open positions between the fully closed andfully opened positions. When so provided, the pre-characterizedrelationship between the pressure drop across the characterized port andthe flow rate may depend on the current axial positioning of valvesealing member 22.

In some instances, valve controller 26 may include a determining block,which may include a microcontroller 36 or the like, which may include orbe in communication with a memory, such as a non-volatile memory 37.Alternatively, or in addition, determining block (e.g. microcontroller36) may be coupled to or may be configured within valve control block orvalve controller 26. Determining block may be configured to store and/ormonitor one or more parameters, which may be used when determining ameasure that is related to a fluid flow rate through fluid channel 18.Determining block (e.g. microcontroller 36) may be configured to use thestored and/or monitored parameters (e.g. the relationship between apressure drop across a characterized port and the flow rate through thefluid channel 18) stored in the memory 37 to help determine a measurethat is related to a fluid flow rate through fluid path or fluid channel18.

Illustratively, determining block (e.g. microcontroller 36) may beconfigured to determine and/or monitor a measure (e.g., a flow rate offluid passing through the characterized port or other similar ordifferent measure, as desired) based, at least in part, on stored and/ormonitored measures including, but not limited to, measures related topressure drop across a characterized valve port or other pressurerelated measures upstream and downstream of the characterized valveport, a temperature of the fluid flowing through fluid channel 18,and/or a measure related to a current position of valve sealing member22 at gas valve port 20 or the size of an opening at the characterizedport. In one example, a determining block (e.g. microcontroller 36) mayinclude non-volatile memory 37 that is configured to store openingcurves of valve assembly 10, where the opening curves may characterize,at least in part, a flow rate as a function of a sensed axial positionof valve sealing member 22, and a sensed differential pressure across acharacterized valve port 20 or an otherwise determined pressure at oradjacent a characterized valve port 20 (e.g., knowing a set-point of anupstream pneumatic pressure reducing valve (PRV), as the set-pointpressure of the PRV may be substantially equal to the pressure at aninlet of the characterized valve port), and may facilitate determiningan instantaneous and/or cumulative fluid (e.g., fuel) flow in fluidchannel 18 and/or consumption by an appliance in fluid communicationwith valve assembly 10.

It is contemplated that determining block (e.g. microcontroller 36) maycontinuously or non-continuously control, store, and/or monitor aposition (e.g., an axial or rotary position or open/closed state orother position) of valve sealing member 22 within valve port 20, monitora differential pressure across the characterized port, and/or monitor atemperature upstream and/or downstream of the characterized port. Inaddition, microcontroller 36 may continuously or non-continuouslydetermine the flow rate of the fluid passing through the characterizedport, where microcontroller 36 may be configured to record in its memoryor in another location, an instantaneous flow rate of fluid flowingthrough the characterized port, a cumulative flow volume, and/or adetermined instantaneous or cumulative (e.g., total) fluid consumptionbased on the positions of valve sealing member(s) 22 and determined flowrates at an instant of time or over a specified or desired time period.In addition, determining block (e.g. microcontroller 36) may beconfigured to report out the instantaneous flow rate, cumulative flowvolume and/or total or cumulative fluid consumption over a given timeperiod. Determining block (e.g. microcontroller 36) may report theinstantaneous flow rate, cumulative flow rate, and/or total orcumulative consumption of the fluid flowing through the characterizedport to system display 52 of an overall system controller 50 (e.g., abuilding/industrial automation system (BAS/IAS) controller), anappliance display 62 of an appliance controller 60 where the appliancemay be configured to receive the flowing fluid, a display adjacent gasvalve assembly 10, or any other display, device, controller and/ormemory, as desired.

In some instances, valve controller 26 may include or be incommunication with a valve actuator 30, which in conjunction withstepper motor 94 or other device is configured to position valve sealingmember 22 in valve port 20. Valve actuator 30 and/or stepper motor 94may be in communication with microcontroller 36 of valve controller 26,and microcontroller 36 may be configured to control, monitor, and/orrecord the position (e.g., axial position, radial position, etc.) ofvalve sealing member 22 within valve port 20 through valve actuator 30(e.g., valve actuator 30 may be configured to effect the locking (e.g.,valve actuator 30 OFF) or the unlocking (e.g., valve actuator 30 ON) ofthe valve sealing member 22 in a particular position) and stepper motor94 (e.g., stepper motor 94 may be configured to adjust the position ofvalve sealing member 22 when it is not locked in a particular position),or through only stepper motor 94. Alternatively, or in addition,microcontroller 36 may be configured to monitor and record the positionof valve sealing member 22 within valve port 20 through a connectionwith a position sensor 48 or through other means.

Microcontroller 36 may continuously or non-continuously monitor andrecord the position (e.g., axial position, radial position, etc.) ofvalve sealing member 22 within valve port 20 through valve actuator 30and stepper motor 94, and microcontroller 36 may indicate the sensedand/or monitored position of valve sealing member 22 within valve port20 as a prescribed position of valve sealing member 22. The prescribedposition of valve sealing member 22 may be the position at which valvesealing member 22 was and/or is to be located, whereas a position ofvalve sealing member 22 sensed by position sensor system 48 may beconsidered an actual position of valve sealing member 22 within valveport 20.

In some instances, valve controller 26 may be configured to performelectronic operational cycle counting or may include an electroniccounter configured to count each operational valve cycle of valvesealing members 22 during, for example, the lifetime of gas valveassembly 10 or during some other time period. In some cases,microprocessor 36 of valve controller 26 may be configured to monitor atotal number of operational cycles (e.g., the number of times fuel valvesealing members 22 are operated from a closed position to an openposition and back to a closed position) of valve ports 20 and measuresrelated thereto. In some cases, microprocessor 36 may store such data ina non-volatile memory, such as memory 37, sometimes in a tamper proofmanner, for record keeping and/or other purposes. Microprocessor 36 maymonitor the number of cycles of valve sealing members 22 in one or moreof several different manners. For example, microprocessor 36 may monitorthe number of cycles of valve sealing members 22 by monitoring thenumber of times first main valve switch 72 and/or second main valveswitch 74 are powered or, where one or more control signals may beprovided to fuel valve actuator(s) 30 controlling when fuel valveactuator(s) 30 selectively moves (e.g., opens or closes) valve sealingmember(s) 22, microprocessor 36 may monitor the one or more controlsignals.

Valve controller 26, in some cases, may monitor main valve switches 72,74 by receiving signals directly from a device located remotely fromvalve assembly 10 on which main valve switches 72, 74 may be located(e.g. see FIGS. 11-12). Switches ((main valve switches 72, 74 and safetyswitch 70 (discussed below)) may be any mechanism capable of performinga switching function including, but not limited to, relays, transistorsand/or other solid state switches and circuit devices and/or otherswitches. Valve controller 26 may include a electrical port, sometimesseparate from a communications interface 110 (discussed below), forreceiving one or more control signals from the device located remotelyfrom valve assembly 10. The one or more control signals received via theelectrical port may include, but are not limited to: a first valve port20 a control signal that, at least in part, may control the position offirst valve sealing member 22 a via first valve actuator 30 a, and asecond valve port 20 b control signal that, at least in part, maycontrol the position second valve sealing member 22 b via second valveactuator 30 b.

As an alternative to monitoring control signals, or in addition,microprocessor 36 may monitor the number of cycles of valve sealingmembers 22 by monitoring data from a position sensor 48. For example,microprocessor 36 of valve controller 26 may monitor position sensor 48and record the number of times valve sealing members 22 are in an openposition after being in a closed position and/or the number of timesvalve sealing members 22 are in a closed position after being in an openposition and/or the number of times valve sealing members are operatedfrom a close position to an open position and back to a closed position.These are just some examples. Further, if valve controller 26 isoperating valve sealing members 22, valve controller 26 may monitor thenumber of operational cycles by counting its own control signals sent tovalve actuators 30 and/or stepper motors 94.

The non-volatile memory 37, which may maintain and/or store the numberof operational valve cycles, may be positioned directly on, or packagedwith, valve body 12 (e.g., on or within memory of microcontroller 36)and/or may be accessible by valve controller 26. Such storage, placementand/or packaging of valve cycle data may allow for replacement ofcomponents in the overall system (e.g., an appliance control 60, etc.)without losing the valve cycle data. In an illustrative instance, valvecycle data may be securely stored, such that it may not be tamperedwith. For example, the valve cycle data may be stored the non-volatilememory 37 of valve controller 26 and the valve cycle data may bepassword protected.

Microcontroller 36 of valve assembly 10 may be configured to compare acount of a total number of operational cycles of valve sealing members22 to a threshold number of operational cycles. In an instance where thecounted number of operational cycles of the valve sealing member(s) 22 tapproaches, meets, or exceeds the threshold number of cycles,microcontroller 36 may initiate a warning and/or request a switch 69 ina limit string 67 to open and thus, remove or cut power to valveswitches 72, 74 and fuel valve actuator(s) 30. Alternatively, or inaddition, microcontroller 36 may send a signal to initiate an alarmand/or put the system in a safety lockout, or microcontroller 36 may beconfigured to take other action as desired. Illustratively,microcontroller 36 may be configured to prevent fuel valve actuator(s)30 from allowing valve sealing member(s) 22 to open after the totalnumber of operational cycles meets and/or exceeds the threshold numberof operational cycles. In some instances, the threshold number of cyclesmay be related to the number of cycles for which valve assembly 10 israted (e.g., a maximum number of cycles before failures might beexpected, etc.) or related to any other benchmark value. In addition,microcontroller 36 may be configured to perform other diagnostics basedon analyzing captured operational cycle data, where the otherdiagnostics may include number of cycles, time duration of cycles, andsimilar or different diagnostics, as desired.

Valve controller 26 may include an I/O or communications interface 110with a communication protocol for transmitting data to and/or otherwisecommunicating with one or more remote device(s) that may be locatedremotely from valve assembly 10 (e.g., a combustion appliance includingcontroller 60 located remotely from valve assembly 10). Communicationsinterface 110 may be a wired or wireless communication interface, wherethe wired or wireless communication interface 110 may be configured tobe compatible with a predetermined communication bus protocol or othercommunication protocol. A wired link may be low voltage (e.g. 24V, 5V,3V, etc.), which may reduce certain issues related to line-voltagewiring schemes. Illustratively, communications interface 110, using thepredetermined communication bus protocol or other communicationprotocol, may be configured to output and/or communicate one or morevalve conditions, one or more measures related to valve conditions, oneor more conditions related to a fluid flow through fluid channel 18,and/or one or more diagnostic parameters, conditions or events, to adevice located adjacent or remote from valve assembly 10.

As discussed, valve controller 26 may be configured to determine one ormore valve conditions based on one or more diagnostic parameters relatedto fluid channel 18 sensed by one or more sensor(s) (e.g., a pressuresensor, etc.) in communication with fluid channel 18. The diagnosticparameters may be determined by valve controller 26 and stored in anon-volatile memory 37 or other memory accessible by valve controller26. The diagnostic parameters may include, but are not limited to, atotal number of operational cycles, a fuel usage parameter, one or morefault history parameters, one or more user or factory or other settingparameters, self diagnostic check parameters, fault parameters and/orother similar or dissimilar parameters, as desired. The communicatedvalve condition(s) or measure(s) related to the valve condition(s) maybe determined by valve controller 26 or one or more remote devices.Illustrative valve conditions and measures related to valve conditionsmay include, but are not limited to: high fuel pressure conditions, lowfuel pressure conditions, valve closure conditions, valve leakconditions, safety event condition, and/or other similar or dissimilarvalve conditions and/or outputs.

In addition to communication interface 110 being configured to outputinformation to a device located adjacent or remote from valve assembly10, communication interface 110 may be configured to receive one or moreinputs from the remote device or an adjacently positioned device.Illustrative inputs may include, but are not limited to: anacknowledgement of reception of one or more of the valve conditions, auser setting, a system setting, a valve command, and/or other similar ordissimilar input.

In some instances, valve controller 26 may communicate through the I/Ointerface or communication interface 110 with a remotely located outputblock 46, where output block 46 may display and/or output a determinedmeasure related to fluid flow rate through fluid channel 18, sometimesalong with other data, information and controls sent from valvecontroller 26 (see, for example, FIGS. 9 and 10). Output block 46 mayinclude a display and/or other remote systems, and microcontroller 36may be configured to send measures to a device control system 60 orbuilding automation system or overall system controller 50 of outputblock 46 for further monitoring and/or analysis. As discussed, the I/Ointerface may include a wired and/or wireless interface between valvecontroller 26 (e.g., microcontroller 36) and output block 46 systems(e.g., building automation system or overall system controller 50,combustion appliance management system 60, handheld device, laptopcomputer, smart phone, etc.), where the connection between valvecontroller 26 may or may not be made with communication link 100 (e.g.,communication link 100 could, but need not be, the one and only onecommunication link).

In an illustrative operation, valve controller 26 may be utilized in amethod for communicating information between valve assembly 10 and acombustion appliance controller 60, where the combustion appliancecontroller 60 may be associated with a combustion appliance (e.g., adevice separate from, and possibly remotely relative to valve assembly10) for which valve assembly 10 may control a flow of fuel. Theoperation may include sensing, with one or more sensor (e.g., pressuresensor assembly 24), one or more sensed parameters within fluid channel18 of valve assembly 10. The sensed parameter may be stored in anon-volatile memory 37, or other memory, of valve controller 26. Valvecontroller 26 may determine one or more valve conditions (e.g., a safetyevent condition) based on the one or more sensed parameters. Forexample, valve controller 26 may compare the one or more sensedparameters to a threshold parameter to determine one or more valveconditions. If one or more valve conditions have been determined, valvecontroller 26 may be configured to send information that may be relatedto the one or more determined valve conditions from valve assembly 10 tothe combustion appliance controller 60 (or other controller or device)across a communication link or bus 100 connected to a communicationsinterface 110.

In one example, upon receiving one or more determined valve conditions,such as a safety event condition, combustion appliance controller 60 (orother controller or device) may be configured to open safety switch 70,such that power to a valve control signal that is coupled to one or morevalve actuators 30 is cut, thereby automatically closing one or morevalve ports 20 (e.g., closing valve sealing member(s) 22 of valveport(s) 20). In some cases, safety switch 70 may be controlled by analgorithm in combustion appliance controller 60, where an output of thealgorithm is affected by information passed via the communication link100. Additionally, or in the alternative, other feedback signals mayaffect an output of the algorithm, where the other feedback signals mayor may not be passed via the communication link 100 and may or may notoriginate from valve assembly 10.

In other illustrative operations, a low gas pressure/high gas pressureevent may be reported from valve controller 26 to combustion appliancecontroller 60. In response to receiving a reported low gas pressure/highgas pressure event, combustion appliance controller 60 may be configuredto open safety switch 70. Further, in cases where a proof of closureevent is reported to combustion appliance controller 60 prior toignition of the combustion appliance, an ignition sequence may not bestarted. In certain other instances where a Valve Proving System (VPS)sequence test is being performed, a combustion appliance controller 60may use reported results of the VPS sequence test to make an evaluation.For example, if in the evaluation of the VPS test it were determinedthat a valve was leaking, the appliance controller 60 might beprogrammed to open safety switch 70, to initiate a safety lockout, toinitiate an alarm, and/or to take any other similar or dissimilarmeasure.

In other scenarios, valve assembly 10 may be used as a control valve andin that case, valve controller 26 may send a signal to combustionappliance controller 60 indicative of a valve position, and combustionsappliance controller 60 may respond accordingly. These other scenarios,for example, may be applied in parallel positioning system applications,low fire switch applications, auxiliary switch applications, etc.Additionally, it is contemplated that valve controller 26 may interactwith remote devices in other similar and dissimilar manners within thespirit of this disclosure.

Pressure block or pressure sensor assembly 24 may be included in flowmodule 28, as seen in FIGS. 9 and 10, and/or pressure sensor assembly 24may be at least partially separate from flow module 28. Pressure sensorassembly 24 may be configured to continuously or non-continuously sensepressure or a measure related to pressure upstream and/or downstream ofa characterized port and/or along other portions of fluid channel 18.Although pressure sensor assembly 24 may additionally, or alternatively,include a mass or volume flow meter to measure a flow of fluid throughfluid channel 18, it has been contemplated that such meters may be moreexpensive and difficult to place within or outside the valve assembly10; thus, a useful, relatively low cost alternative and/or additionalsolution may include placing pressure sensors 38, 42, 43, 44 and/orother pressure sensors within, about and/or integrated in valve body 12of valve assembly 10 to measure the fluid flow through fluid channel 18,the pressures at the input and output ports, and/or other similar ordifferent pressure related measures. Pressure sensors 38, 42, 43, 44 mayinclude any type of pressure sensor element. For example, the pressuresensor element(s) may be MEMS (Micro Electro Mechanical Systems)pressure sensors elements or other similar or different pressure sensorelements such as an absolute pressure sense element, a gauge pressuresense element, or other pressure sense element as desired. Example senseelements may include, but are not limited to, those described in U.S.Pat. Nos. 7,503,221; 7,493,822; 7,216,547; 7,082,835; 6,923,069;6,877,380, and U.S. patent application publications: 2010/0180688;2010/0064818; 2010/00184324; 2007/0095144; and 2003/0167851, all ofwhich are hereby incorporated by reference.

In some cases, pressure sensor assembly 24 may include a differentialpressure sensor 38 for measuring a differential pressure drop across acharacterized valve port 20, or across a different characterized port,as seen in FIG. 9. A pressure sensor assembly 24 including adifferential pressure sensor 38, may be exposed to both a first pressure38 a upstream of a characterized valve port and a second pressure 38 bdownstream of the characterized valve port. Differential pressure sensor38 may send a measure related to the sensed differential pressure to themicrocontroller 36 of valve controller 26, as seen from the diagram ofFIG. 9. Microcontroller 36 may be configured to monitor the differentialpressure across the characterized port with the differential pressuremeasures sensed by differential pressure sensor 38.

Alternatively, or in addition, an illustrative pressure sensor assembly24 may include one or more first pressure sensors 42 upstream of acharacterized valve port and one or more second pressure sensors 43downstream of the characterized valve port, where first and secondpressure sensors 42, 43 may be in fluid communication with fluid channel18 and may be configured to sense one or more measures related to apressure upstream and a pressure downstream, respectively, of thecharacterized valve port, as seen in FIG. 10. Where a second valve port(e.g., second valve port 20 b) may be positioned downstream of a firstcharacterized valve port (e.g. first valve port 20 a) and forming anintermediate volume 19 between first and second valve ports, pressuresensor assembly 24 may include one or more third pressure sensors 44 influid communication with the intermediate volume 19, which may sense oneor more measures related to a pressure in the intermediate volume 19.Where two characterized ports are utilized, first pressure sensors 42may be upstream of both characterized ports, second pressure sensors 43may be downstream of both characterized ports, and third pressuresensors 44 may be downstream from the first characterized port andupstream from the second characterized, but this is not required (e.g.,first and second pressure sensors 42, 43 may be used to estimate thepressure drop across the valves). Additionally, or in the alternative,one or more differential pressure sensors 38 may be utilized to estimatethe pressure drop across the first characterized port and/or the secondcharacterized port. It is further contemplated that valve ports 20 maynot be characterized ports.

Pressure sensors 42, 43, 44 may be configured to send each of the sensedmeasure(s) directly to microcontroller 36. Microcontroller 36 may beconfigured to save the sensed measures and/or related information to anon-volatile memory 37, and may perform one or more analyses on thereceived sensed measures. For example, microcontroller 36, which may bea portion of flow module 28 and/or valve controller 26, may determine ameasure that is related to a fluid flow rate through the fluid pathbased, at least in part, on the received sensed measures related topressure upstream of the characterized port and on the received sensedmeasures related to pressure downstream of the characterized port.

Where a valve assembly 10 includes one or more valve ports 20, pressuresensor assembly 24 may include first pressure sensor 42 positionedupstream of first valve port 20 a at or downstream of inlet port 14, asseen in FIG. 11. In addition, or alternatively, pressure sensor assembly24 may include a second pressure sensor 43 positioned downstream ofsecond valve port 20 b at or upstream from outlet port 16. Valveassembly 10 may further include one or more third pressure sensors 44downstream of first valve port 20 a and upstream of second valve port 20b. Pressure sensors 42, 43, 44 may be configured to sense a pressureand/or a measure related to the pressure in fluid channel 18, and tocommunicate the sensed measures to valve controller 26, which isphysically coupled to or positioned within valve body 12. Where multiplepressure sensors 42, 43, 44 exist at or near one or more location (e.g.,upstream of valve ports 20, intermediate of valve ports 20, downstreamof valve ports 20, etc.) along fluid channel 18, at least one of themultiple pressure sensors may be configured to sense pressures over apressure sub-range different from a sub-range over which at least oneother of the multiple pressure sensors at the location may be configuredto sense pressure, but this is not required. In some cases, and as shownin FIG. 8, the various pressure sensors may be mounted directly to acorresponding circuit board, such that when the circuit board is mountedto the valve body 12, the pressure sensor is in fluid communication witha corresponding fluid port in the valve body 12.

In some instances, such arrangements of pressure sensors 38, 42, 43, 44within valve assembly 10, along with the connection between valvecontroller 26 and pressure sensors 38, 42, 43, 44 may be used to emulatefunctions of high gas pressure (HGP) and low gas pressure (LGP)switches, which traditionally require wires and further housingsextending to and from and/or attached to valve body 12. When theelectronics and elements of valve assembly 10 are configured to emulateLGP/HGP switches, gas-valve wiring connections and interactions may beat least partially avoided, eliminated or simplified. In some instances,such configuration of valve controller 26 and pressure sensors 38, 42,43, 44 may reduce manual operations (e.g., manually adjusting amechanical spring or other device of conventional high gas pressure(HGP) and low gas pressure (LGP) switches), and allow for a more precisefitting with the electronics of valve assembly 10.

In some cases, pressure sensor assembly 24 may include one or moreabsolute pressure sensors 54 in communication with microcontroller 36.Absolute pressure sensor 54 may sense an atmospheric pressure adjacentgas valve assembly 10, and may be configured to communicate and transferdata related to the sensed atmospheric pressure to microcontroller 36.Microcontroller 36 may take into account the atmospheric pressure fromthe absolute pressure sensor 54 when determining the flow rate of fluidflowing through the characterized port and/or an estimate of fuelconsumption by an attached appliance and/or when determining thresholdvalues. Other sensors may be included in valve assembly 10, for example,one other type of sensor may be a barometric pressure sensor.

As discussed, valve assembly 10 and the flow module 28 thereof mayinclude temperature sensor(s) 34, as seen in FIGS. 9-11. Temperaturesensor 34 may be positioned within valve body 12 so as to be at leastpartially exposed to fluid channel 18 and configured to sense atemperature of a fluid (e.g., gas or liquid) flowing through fluidchannel 18 and/or any other temperature in fluid channel 18. Temperaturesensor 34 may have a first temperature sensor 34 a at least partiallyexposed to fluid channel 18 upstream of a characterized valve port,and/or a second temperature sensor 34 b at least partially exposed tofluid channel 18 downstream of the characterized valve port, as seen inFIGS. 9 and 10. When there is a first valve port and a second valve port(e.g., valve ports 20 a, 20 b), there may be a third temperature sensor34 c in fluid communication with intermediate volume 19 between thefirst and second characterized valve ports, if desired. The sensedtemperature measure may be used by flow module 28 to, for example,compensate, correct, or modify a determined measure (e.g., a density ofa fluid) that is related to, for example, a fluid flow rate of fluidflowing through fluid channel 18, which may help improve the accuracy ofthe flow rate calculation. In operation, temperature sensor 34 (e.g.,any or all of temperatures sensors 34 a, 34 b, 34 c) may communicate asensed temperature measure directly or indirectly to valve controller 26and/or a non-volatile memory 37 of valve controller 26 (e.g., memory ina microcontroller 36 or memory in another location) and/or flow module28. Valve controller 26 may, in turn, utilize the sensed temperature tohelp increase the accuracy of a determined flow rate of fluid passingthrough a characterized port and/or increase the accuracy of acalculated fluid and/or fuel consumption quantity, as desired, and storethe calculated flow rate of fluid passing through a characterized portand/or the calculated fluid and/or fuel consumption quantity in thenon-volatile memory 37. Additionally, or in the alternative, in someinstances pressure sensors 38, 42, 43, 44 may utilize built-intemperature sensors that are used to internally compensate the pressuresensor over the operating temperature range. In such instances, thetemperature reading may be accessible at the pressure sensor output(e.g., a digital communication bus) or at another location.

Flow module 28 of valve assembly 10 may further include a positionsensor system that may be configured to continuously or discontinuouslysense at least one or more of an axial position, a rotary position,and/or a radial position, of valve sealing member 22 within or aboutfluid valve port 20. In some cases, position sensor system may includemore than one position sensors 48, such that each position sensor 48 maymonitor a sub-range of a valve's total travel. Moreover, position sensorsystem may be utilized as a proof of closure switch system. Positionsensor(s) 48 of the position sensor system may be situated or positionedin valve body 12 at or about a valve port 20. For example, and in someinstances, position sensor(s) 48 may be fluidly isolated from fluidchannel 18 (e.g., fluidly isolated from fluid channel 18 by valve body12), and radially spaced from an axis upon which a valve sealingmember(s) 22 may axially and/or rotationally translate between a closedposition and an open position, as seen in FIGS. 14-17.

An illustrative gas valve assembly 10 may include a first valve port 20a and a second valve port 20 b (see FIG. 7), and a first position sensor48 a monitoring first valve sealing member 22 a and a second positionsensor 48 b monitoring second valve sealing member 22 b, where positionsensors 48 a, 48 b may be separate devices or may share an enclosureand/or other parts. In the illustrative instance, the first positionsensor 48 a may be fluidly isolated from fluid channel 18 and radiallyspaced from a first axis of first valve port 20 a, and the secondposition sensor 48 b may be fluidly isolated from fluid channel 18 andradially spaced from a second axis of second valve port 20 b (see FIGS.14-17).

As discussed above, position sensor 48 may be configured to detect ameasure that is related to whether valve sealing member 22 is in an openor closed position and/or a measure related to an intermediate positionof valve sealing member 22 within fluid valve port 20. In one example,position sensor(s) 48 may be configured to provide a proof of closure(POC) sensor(s) for valve port(s) 20 (e.g., first valve port 20 a and/orsecond valve port 20 b).

Where valve sealing member(s) 22 have a range of travel (e.g.,rotationally and/or axially) within valve port(s) 20, position sensor(s)48 may be configured to sense a current position of valve sealingmember(s) 22 anywhere along the range of travel of valve sealingmember(s) 22. Position sensor 48 may then send (e.g., through electronicor other communication) sensed positioning data of the measure relatedto the position of valve sealing member 22 to determining block and/ormicrocontroller 36 and/or a non-volatile memory 37 of valve controller26 and/or flow module 28, where microcontroller 36 may be configured tomonitor the axial position of valve sealing member 22 within valve port20 through position sensor system 48.

In some instances, valve controller 26 may include an electronic circuitboard and a wired or wireless communication link 100 may facilitatecommunication between position sensor(s) 48 and the electronic circuitboard or other device of valve controller 26. Valve controller 26 may beconfigured to further pass on positioning information to remote devicesthrough communication lines (e.g., communication link 100) and/ordisplay positioning data of valve sealing member 22 on one or moredisplays 76 attached to valve assembly 10 and/or remote devices, as seenin FIG. 13. Valve controller 26 may indicate a closed or open positionof valve sealing member 22 or a degree (e.g., 10%, 20%, 30%, etc.) of anopening of valve sealing member 22 with one or more visual indicators onor comprising display(s) 76, as seen in FIG. 13, such as one or morelight emitting diodes (LEDs) acting as a visual indication of a valvestate and/or position, liquid crystal displays (LCDs), a touch screen,other user interfaces and/or any other display interfacing with ordisplaying information to a user.

In some instances, the position sensor system may include one or moreswitches 64 (e.g., a first switch 64 a and a second switch 64 b, whereswitch(es) 64 may be or may include relays or other switch types such asFETs, TRIACS, etc.) having one or more switched signal paths 66 and oneor more control inputs 68 (e.g., a first control input 68 a and a secondcontrol input 68 b), as seen in FIG. 13. Illustratively, one switch 64may be utilized for multiple position sensors 48, or more than oneswitch 64 may be utilized for multiple position sensors (e.g., in a 1-1manner or other manner), as desired. Control input 68 may set the stateof switched signal paths 66 to a first state or a second state oranother state, as desired. As depicted in FIG. 13, valve controller 26may be coupled to position sensor(s) 48, and may control input 68 ofswitch 64, where both valve controller 26 and position sensors 48 may beisolated from fluid communication with fluid channel 18. In someinstances, valve controller 26 may be configured to set the state ofswitched signal path 66 to the first state when first position sensor 48a senses that a first valve port 20 a is not closed or first valvesealing member 22 a is not in a closed position, and to a second statewhen position sensor 48 senses that a first valve port 20 a is closed orfirst valve sealing member 22 a is in a closed position. Similarly,valve controller 26 may be configured to set the state of switchedsignal path 66 to the first state when second sensor 48 b senses thatsecond valve port 20 b is not closed or second valve sealing member 22 bis not in a closed position, and to a second state when position sensor48 senses that a second valve port 20 b is closed or second valvesealing member 22 b is in a closed position. In the alternative, valvecontroller 26 may be configured to set the state of switched signal path66 to the first state when at least one of the first and second sensorsvalve ports 20 a, 20 b are not closed or at least one of the first andsecond valve sealing members 22 a, 22 b are not in a closed position,and to a second state when position sensor 48 senses that both first andsecond valve ports 20 a, 20 b are closed or both first and second valvesealing members 22 a, 22 b are in closed positions. Similar or identicalor different processes, as desired, may be utilized for each positionswitch 64 and control input 68.

Illustratively, valve sealing member(s) 22 may include a sensor element80, and position sensor(s) 48 may include one or more transducer orfield sensors 82. For example, valve sealing member(s) 22 may include asensor element 80 (e.g., a magnet when using a field sensor 82, aferrous core when using a linear variable differential transformer(LVDT) 84, or other sense element, and/or similar or dissimilarindicators) secured relative to and translatable with valve sealingmember(s) 22. Position sensor(s) 48 may include one or more fieldsensors 82 (e.g., magnetic field sensors, a LVDT 84, Hall Effect sensorsor other similar or dissimilar sensors), as seen in FIGS. 14-15. Fieldsensor 82 may be positioned within valve body 12 or may be positionedexterior to valve body 12 and radially spaced from a longitudinal axisof valve port(s) 20 and/or valve sealing member(s) 22. Positionsensor(s) 48 may be positioned so as to be entirely exterior to fluidchannel 18. The meaning of entirely exterior of fluid channel 18 mayinclude all position sensors 48 and all electronics (e.g., wires,circuit boards) connected to position sensor(s) 48 being exterior tofluid channel 18. Where position sensor(s) 48 includes an LVDT, the LVDTmay be positioned concentrically around and radially spaced from valvesealing member(s) 22, as shown in FIG. 15, and/or the axis of LVDT maybe spaced radially and parallel from the valve sealing members 22.

In some cases, a strain gauge 86, as depicted in FIG. 16, or otherelectromechanical sensor may also be utilized to sense a position ofvalve sealing member 22 within an interior of fluid channel 18 from aposition fluidly exterior of fluid channel 18 by sensing a strain levelapplied by spring 31 in communication with valve sealing member 22.Alternatively, or in addition, valve sealing member(s) 22 may includeone or more visual indicators 88 (e.g., a light reflector or othervisual indicators), and position sensor(s) 48 may include one or moreoptical sensors 90, as seen in FIG. 17, where visual indicators may beany indicators configured to be viewed by optical sensors through atransparent window 87 sealed with an o-ring or seal 89 or throughanother configuration, such that optical sensors 90 may determine atleast whether valve sealing member(s) 22 is/are in a closed or openposition. Where a visual position indicator 88 is utilized, and in somecases, a user may be able to visually determine when valve sealingmember(s) 22 is not in a closed position.

As may be inferred from the disclosure, position sensor 48 may in someinstances operate by detecting a position of a valve sealing member 22and/or optionally valve stem 92 or the like within a valve assembly 10having a valve body 12, where valve sealing member 22 may betranslatable with respect to valve port 20 of valve body 12 along atranslation or longitudinal axis “A” within a valve port 20. In somecases, sensor element 80, affixed relative to valve sealing member 22,may be positioned within the interior of valve body 12 and mayoptionally fluidly communicate with fluid channel 18; however, positionsensor 48 may be isolated from fluid channel 18 and/or positionedexterior to valve body 12. In an illustrative embodiment, valve sealingmember 22 may be positioned at a first position within an interior ofvalve port 20 along translation axis A. The first position of the valvesealing member 22 may be sensed with position sensor 48 by sensing alocation of a sensor element 80 secured relative to valve sealing member22 with position sensor 48. Then, position sensor 48 may automaticallyor upon request and/or continuously or discontinuously, send the sensedlocation and/or open or closed state of valve sealing member 22 to thevalve controller 26.

It is contemplated that valve controller 26 may electronically calibratethe closed position of valve sealing member 22 and/or valve stem 92.Such a calibration may store the position of the valve sealing member 22and/or valve stem 92 when the valve sealing member 22 and/or valve stem92 is in a known closed position (e.g. such as during installation ofthe valve assembly 10). During subsequent operation, the position of thevalve sealing member 22 and/or valve stem 92 can be compared to thestored position to determine if the valve sealing member 22 and/or valvestem 92 is in the closed position. A similar approach may be used toelectronically calibrate other positions of the valve sealing member 22and/or valve stem 92 (e.g. fully open position, or some intermediateposition), as desired.

Fuel Rate Monitor

In operation, valve assembly 10 may be utilized to measure a flow rateof fluid flowing through a characterized port (e.g., valve port 20 orother port). As discussed above, the measuring method may includeutilizing a microcontroller 36 or the like to monitor (e.g., monitoringsensed measures, monitoring control signals, set-points, and usersettings, etc.) a differential pressure across a characterized valveport which may be continuously or discontinuously monitored by pressuresensor assembly 24, monitoring (e.g., monitoring sensed/feedbackmeasures, monitoring control signals, set-points and user settings,etc.) a position of a valve sealing member 22 within the characterizedvalve port which may be continuously or discontinuously monitored byposition sensor 48, and/or determining a flow rate of the fluid flowingthrough the characterized port with the microcontroller 36 from themonitored differential pressure, and in some cases, the monitoredposition of the valve sealing member 22.

To facilitate determining the flow rate of fluid flowing through thecharacterized port, microcontroller 36 may utilize a valve's openingcurves stored in a memory 37. In some cases, the characterized port maybe characterized at various flow rates, across various open positions,to identify a relationship between a measured pressure drop across thecharacterized port and the flow rate through the gas valve. Of course,when the valve only switches between a fully closed position and a fullyopen position, the characterized port need not be characterized overvarious open positions; just over the fully open position. In somecases, the relationship may be stored in a non-volatile memory 37 of thegas valve assembly 10.

Through the use of valve opening curves and/or other similar ordifferent data and/or algorithms, microcontroller 36 may determine aflow rate for any combination of sensed pressure drop and sensed valvesealing member 22 positions. As further detailed herein, it iscontemplated that temperature, atmospheric pressure, inlet pressure,outlet pressure and/or other sensed parameters may be used to helpincrease the accuracy of the determined flow rate, if desired.

Microcontroller 36 may be configured to continuously monitor thedifferential pressure across the characterized port, and in some casescontinuously monitor the position of the valve sealing member 22, insuch a manner as to be configured to continuously determine the flowrate of the fluid flowing through the valve port. Continuouslymonitoring the differential pressure(s) and in some cases thepositioning of the valve sealing member 22, and continuously determiningthe flow rate of fluid flowing through the characterized port, mayfacilitate the microcontroller 36 continuously tracking, reporting,and/or outputting an instantaneous flow rate of the fluid flowingthrough the characterized port and/or to continuously tracking,reporting, and outputting a cumulative flow volume of the fluid(integral of the flow rate over time) flowing through the characterizedport over a given period of time. An average flow rate of fluid flowingthrough the characterized port may be determined from the instantaneousflow rates of the fluid over time. In addition, microcontroller 36 maysend one or more of the tracked and reported instantaneous flow ratesand/or the cumulative flow volume from microcontroller 36 to a systemcontroller 50 and/or an appliance controller 60 via a communication link100, if desired, and the reported instantaneous flow rates and/or thecumulative flow volume and/or other data may be read out at the localvalve controller display 76, appliance display 62 and/or system display52.

In addition to taking into consideration differential pressure across acharacterized port, and in some cases the positioning of valve sealingmember 22 (e.g. when intermediate open positions are used),microcontroller 36 may consider measures from one or more other sensorsthat sense characteristics within or about fluid channel 18 or otherresources. For example, microcontroller 36 may consider one or moremeasures related to a temperature in fluid channel 18 sensed bytemperature sensor(s) 34 (e.g., temperature may be used tocorrect/calculate a fluid flow rate), one or more measures related to anabsolute pressure about fluid channel 18 sensed by an absolute pressuresensor 54 (e.g., absolute pressure may be used to correct/calculate flowrate of a fluid), and/or other measures sensed by other sensors orreceived from other sources, as desired.

It is also contemplated that microcontroller 36 may take intoconsideration the altitude of the fluid channel 18 with respect to sealevel or another baseline measure when determining a flow rate of fluidthrough fluid channel 18. Altitude may be continuously ordiscontinuously sensed by an altimeter on or adjacent or remotelylocated from valve assembly 10 and/or an altitude may be preset withinmicrocontroller 36 or entered at any time prior to or during or afterinstallation of the valve assembly 10. Also, it is contemplated that aWobbe index associated with the fluid flowing through fluid channel 18may be stored and utilized. Utilization of a Wobbe index may facilitatereporting out of fluid flow rates through fluid channel 18 bymicrocontroller 36 in units of energy per time (e.g., BTU/hour forindicating fuel consumption), rather than reporting a volumetric or massflow measure. Such consideration of further characteristics (includingcharacteristics not listed) related to fluid channel 18 may allow fordetermining more accurate flow rate measures of the fluid flowingthrough fluid channel 18, as the utilizing of further characteristicsmay have the ability to reduce assumptions in known flowequations/algorithms utilized by microcontroller 36.

Electronic Cycle Counting

In operation, gas valve assembly 10 may monitor the number ofoperational valve cycles experienced by one or more valve sealing member22 over a period of time (such as the lifetime of gas valve assembly10). In one example, valve controller 26 of valve assembly 10 maymonitor a valve sealing member 22 of at least one of the valve ports 20being opened from a closed position and/or being returned to the closedposition to complete an operational cycle, where a plurality ofoperational cycles may be completed during the lifetime of the valveassembly 10. In one example, a count of the number of operational cyclesmay be maintained and/or stored in a non-volatile memory 37, or othermemory, of valve controller 26 (e.g., microcontroller 36 or otherdevice) of valve assembly 10 in a tamper proof manner. Alternatively,and to detect an operation cycle, valve controller 26 of valve assembly10 may monitor a valve sealing member 22 moving from an open position toa closed position and back to an open position, or any other cycleinvolving movement of valve sealing member 22 and/or other parts,portions or devices of valve assembly 10. In some cases, valvecontroller 26 may monitor valve actuators 30, positions of valve sealingmember 22 and/or signals to valve actuators 30, and/or other indicatorsto monitor the number of operational valve cycles experienced by eachvalve port 20 over a period of time, such as the lifetime of valveassembly 10.

The memory (e.g., non-volatile memory 37) of valve controller 26 storingthe electronic operational valve cycle counting system may also beprogrammed with one or more number of cycles for which valve assembly 10may be rated (e.g., one or more threshold numbers of operational valvecycles). Valve controller 26 may be configured to retrieve the one ormore threshold numbers of operational valve cycles from the non-volatilememory 37, and compare the count of the number of operational valvecycles to the one or more threshold numbers of operational valve cycles.If desired, valve assembly 10 may be configured to take action if acounted number of cycles meets and/or exceeds one of the one or morethreshold numbers of valve cycles. Taking action may include, forexample, after a first threshold number of operational cycles has beensurpassed, initiating a warning or an alarm 78 or sending for amaintenance call, and after a second threshold number of operationalcycles has been surpassed, shutting the system down by removing powerfrom main valve switches 72, 74, preventing valve actuator(s) 30 fromselectively moving valve sealing member(s) 22 (e.g., preventing theopening of valve port(s) 20), and/or any other desired action.

As the operational valve cycle data may be electronically stored inmemory (e.g., non-volatile memory 37) of microcontroller 36, the valvecycle data (e.g., a total number of operational cycles, etc.) may becommunicated and/or outputted to one or more remote devices, such assystem controller 50 and/or appliance controller 60, via a wired orwireless communication interface including or connected to a bus or link100 or other link, where the operational valve cycle data (e.g., totalnumber of operational cycles, etc.) may be displayed on displays 52, 62or other display interfaces. Alternatively, or in addition, theoperational valve cycle data may be displayed on a handheld deviceand/or a display at or adjacent valve assembly 10 (e.g., a touch-screenon valve body 12) or on another display or device, as desired.

In addition, microcontroller 36 may be configured to continuously ordiscontinuously monitor and/or analyze the duration and number ofcycles, time between half cycles (time between the open and closing ofthe valve), and/or other parameters to help determine any abnormalpatterns that would be indicative of system or component malfunctionand/or failures, and/or other normal or abnormal patterns. In somefurther illustrative instances, the electronic counter may take theplace of an electronic clock on the system, such that the operationalcycle count may be utilized as a digital time stamp when storinginformation on various events detected by valve controller 26, such asdiagnostic, warning and/or error messages and the like.

Overpressure Diagnostics

Valve assembly 10 may be configured to detect, report, and/orautomatically act upon an overpressure event occurrence at, within,and/or on valve assembly 10. An overpressure event may be an event wherepressure at the input port 14, output port 16, or within fluid channel18 of valve assembly 10 is greater than an overpressure threshold value(e.g., a valve pressure rating value, a pressure value below which thespecifications of the valve assembly 10 are guaranteed, a pressure valuebelow which it is guaranteed no damage will occur to the valve assembly10 from pressure, a pressure value between the pressure value belowwhich the specification of valve assembly 10 is guaranteed and thepressure value below which it is guaranteed no damage will occur to thevalve assembly 10 from pressure, etc.), where the overpressure may causedamage to the valve assembly 10. Acting on such sensed overpressureevents may, for example, take a valve offline until the valve can beinspected, enable more accurate system diagnostics under somecircumstances, optimize maintenance scheduling, minimizing service anddown time, and/or increasing safety levels with respect to valveassembly 10. These are just some examples.

The overpressure threshold value may be related to a valve pressurerating value of valve assembly 10 and/or valve ports 20 therein. Theoverpressure threshold value may be substantially equal to or less thanor greater than the valve pressure rating value of valve assembly 10. Avalve pressure rating value may be any pressure value assigned to valveassembly 10. For example, a valve pressure rating value may be equal toor less than a pressure value at which valve assembly 10 or valve ports20 within valve assembly 10 is or are expected to fail or becomeotherwise damaged.

Similarly, a pressure sensor 38, 42, 43, 44 of pressure sensor assembly24, which may continuously monitor pressure levels of fluid flowingthrough fluid channel 18, may have a sensor pressure rating value. In anillustrative instance, the sensor pressure rating value of at least oneof the pressure sensors 38, 42, 43, 44 may be equal to or substantiallygreater than the valve pressure rating of valve assembly 10. In somecases, there may be multiple overpressure threshold values, which mayindicate different levels of severity of an overpressure event, and/ormay be useful for other purposes or may indicate different thresholds atdifferent locations along the fluid channel 18 (e.g., at the input andoutput of fluid channel 18) where pressure levels are being sensedand/or monitored.

Valve controller 26 of valve assembly 10 may be utilized to facilitateoverpressure diagnostics. Valve controller 26, which may be securedrelative to valve body 12 and in communication with pressure sensorassembly 24, may be configured to compare a measure related to a sensedpressure of fluid (e.g., fuel, etc.) flowing through fluid channel 18 ofvalve body 12 with an overpressure threshold value stored innon-volatile memory 37 or other memory accessible by valve controller26. The sensed pressure may be sensed by pressure sensor assembly 24 atany position along fluid channel or path 18; for example, a pressure maybe sensed upstream of one or more valve port(s) 20 (e.g., first and/orsecond valve port 20 a, 20 b) or downstream of one or more valve port 20(e.g., first and/or second valve port 20 a, 20 b) or if there are two ormore valve ports 20 (e.g., first valve port 20 a and second valve port20 b), then in between, upstream or downstream valve ports 20. Pressuresensor assembly 24 may be configured to utilize one or more pressuresensors 38, 42, 43, 44 that may facilitate continuously sensing apressure in fluid channel 18 at one or more desired locations (e.g.,upstream of a first valve port 20 a) and then automatically andrepeatedly, or continuously, communicate the sensed pressure at thedesired location(s) to valve controller 26.

Valve controller 26 may be configured to determine if the measurerelated to the sensed pressure exceeds or surpasses the overpressurethreshold value. If the measure does surpass the overpressure thresholdvalue, the valve controller 26 may be configured to provide apredetermined output signal indicating that an over pressure event hasoccurred. The predetermined output signal may be provided to a remotedevice (e.g. 50 or 60) and/or an audible and/or visual alarm may bedisplayed on a remote display (e.g., 52, 62) or a display locatedadjacent and/or on valve assembly 10. Alternatively, or in addition, thepredetermined output signal may, indirectly or directly, cause valveactuator(s) 30 to close valve port(s) 20 (e.g., by closing valve sealingmember(s) 22 therein) and/or cause valve controller 26 to store the overpressure event in a non-volatile memory 37 or other memory of valvecontroller 26 and/or other device. The predetermined output signal mayalso, indirectly or directly, cause valve controller 26 to store one ormore of a time stamp of the overpressure event, a level of the sensedpressure causing the overpressure event, a duration of the overpressureevent, a cumulative number of overpressure events, classificationidentifier of the overpressure event, any parameter calculated from aseries of measured pressure readings, and/or other related or unrelateddata.

The stored data or information related to the overpressure events may beprocessed and/or analyzed by valve controller 26 and/or transferred toother devices. Processing the stored information may include, but is notlimited to, determining a most likely cause of an over pressure event,classifying the event by most likely cause, estimating the severity ofthe event, calculating the cumulative number of over pressure events,comparing any of the stored information (e.g., level of the sensedpressure causing the event, time stamp of an event, duration of anevent, number of events, severity of an event, etc.), which may bestored in valve controller 26, to one or more threshold values that mayalso be stored in valve controller 26 or at one or more other locations,notifying a user by visual or audible means or alarm, running selfchecking diagnostics to evaluate key performance characteristics (e.g.,seat leakage testing through a VPS test, regulator performance etc.),indirectly or directly closing valve port(s) 20 via valve actuator(s)30, and/or sending a signal to trigger some system level overpressurecountermeasure in response to a measure surpassing a respectivethreshold value. Additionally, all or some or none of the actions and/orresults of the processing may be communicated to users or other devicesover communication link 100, an I/O interface, and/or any othercommunication mechanism.

High Gas Pressure and Low Gas Pressure Detection

Valve assembly 10 may be configured to monitor the occurrence ofpressure events along a fluid channel 18. Valve assembly 10 may beconfigured as an electronic module for detecting low gas pressure (LGP)upstream of first valve port 20 a and high gas pressure (HGP) downstreamof the first valve port 20 a and/or second valve port 20 b or anothervalve port 20 depending on which valve port 20 is the most downstreamvalve port 20 in valve assembly 10. By placing a pressure sensor 42upstream of the first valve port 20 to sense an inlet gas pressureand/or placing a pressure sensor 42 downstream of the second valve port20 to sense an outlet gas pressure and/or placing a pressure sensor 42in an intermediate volume 19 between a first valve port 20 a and asecond valve port 20 b to sense an intermediate volume gas pressure, theelectronics of valve assembly 10 may be configured to electronicallyemulate and/or perform electromechanical or mechanical HGP/LGP switchfunctions, such that the functions of electromechanical or mechanicalHGP/LGP switches may be directly integrated in valve assembly 10. At aminimum, a single pressure sensor is needed to perform both HGP/LGPswitch functions in accordance with this disclosure. The integration ofthe switch functions may facilitate internalizing wiring connectionswithin valve body 12, and may result in size and cost savings due, atleast in part, to valve and switch functions sharing a common housing,while providing other solutions and benefits as would be generallyrealized.

In an illustrative instance, one or more first pressure sensors 42,positioned upstream of first valve port 20 a, may continuously ordiscontinuously sense an inlet pressure in fluid channel 18 and may bein communication with valve controller 26. Valve controller 26 may beconfigured to continuously or discontinuously compare a first measure(e.g., inlet pressure) or data related thereto, which may be stored inmemory (e.g., non-volatile memory 37) of valve controller 26, that atleast tracks a measure related to a sensed pressure sensed by the one ormore first pressure sensors 42 in valve body 12 upstream of first valveport 20 a, with a first pressure threshold programmed into and stored inmemory (e.g., non-volatile memory 37) of valve controller 26. Valvecontroller 26 may then provide a predetermined first output signal ifthe first measure surpasses the first pressure threshold, where thefirst output signal may result in first valve actuator 30 a closingfirst valve port 20 a and second valve actuator 30 b closing secondvalve port 20 b.

In an illustrative example, valve controller 26 may compare the firstmeasure to a low gas pressure threshold (e.g., a first pressurethreshold) and if the first measure drops below or is less than the lowgas pressure threshold, the first measure may be said to have surpassedthe low pressure threshold, and valve controller 26 may provide thepredetermined first output signal. Alternatively, or in addition, valvecontroller 26 may be configured to compare the first measure with asecond pressure threshold (e.g., a high gas pressure threshold)programmed into and stored in valve controller 26, where valvecontroller 26 may be configured to provide a predetermined second outputsignal if the first measure surpasses the second pressure threshold(e.g., if the first measure is greater than or more than the highpressure threshold). The first and second pressure thresholds may beautomatically, manually through a user interface, locally (e.g., on avalve assembly's 10 own display/user interface 76), and/or remotely(e.g., via an appliance or system level display 52, 62 and communicationbus 100) determined and programmed during setup. In some cases, thefirst and second pressure thresholds may be selectable from the AmericanNational Standards Institute (ANSI) standards and/or European (EN)standards. For example, a first or high gas pressure threshold may be125% of a first pressure run and a second or low gas pressure thresholdmay be 75% of a first pressure run. The predetermined first and secondpressure output signal may indicate a pressure event has occurred and/orother data or information related to the pressure event.

Likewise, one or more second pressure sensors 43 positioned downstreamof first valve port 20 a and/or second valve port 20 b may continuouslyor discontinuously sense outlet pressures in fluid channel 18 and may bein communication with valve controller 26. Valve controller 26 may beconfigured to continuously or discontinuously compare a second measure(e.g., outlet pressure) or data related thereto, which may be stored inmemory (e.g., non-volatile memory 37) of valve controller 26, that atleast tracks a sensed pressure in valve body 12 downstream of secondvalve port 20 b with a third pressure threshold or other pressurethreshold programmed into and stored in memory (e.g., non-volatilememory 37) of valve controller 26. Valve controller 26 may then providea predetermined third output signal if the second measure surpasses thethird pressure threshold, where the third output signal may result infirst valve actuator 30 a closing first valve port 20 a and second valveactuator 30 b closing second valve port 20 b.

In an illustrative example, valve controller 26 may compare the secondmeasure to a high gas pressure threshold and if the second measure risesabove the high gas pressure threshold, the second measure may be said tohave surpassed the high gas pressure threshold and valve controller 26may provide the predetermined third output signal. Alternatively, or inaddition, valve controller 26 may be configured to compare the secondmeasure with a fourth pressure threshold (e.g., a low pressurethreshold), or other pressure threshold, programmed into and stored invalve controller 26, where valve controller 26 may be configured toprovide a predetermined fourth output signal if the second measuresurpasses the fourth pressure threshold. The predetermined third andfourth output signals may indicate a pressure event has occurred and/orother data or information related to the pressure event.

In a similar manner, one or more third pressure sensors 44 positioneddownstream of first valve port 20 a and upstream of second valve port 20b may continuously or discontinuously sense an intermediate pressure, ora measure related thereto, in intermediate volume 19 of fluid channel 18and may be in communication with valve controller 26. Valve controller26 may be configured to continuously or discontinuously compare a thirdmeasure (e.g., intermediate pressure) or data related thereto, which maybe stored in memory (e.g., non-volatile memory 37) of valve controller26 with a fifth pressure threshold or other pressure thresholdprogrammed into and stored in memory (e.g., non-volatile memory 37) ofvalve controller 26. Valve controller 26 may then provide apredetermined fifth output signal if the third measure surpasses thefifth pressure threshold, where the fifth output signal may result infirst valve actuator 30 a closing first valve port 20 a and second valveactuator 30 b closing second valve port 20 b.

In an illustrative example, valve controller 26 may compare the thirdmeasure to a high gas pressure threshold and if the third measure risesabove the high gas pressure threshold, valve controller 26 may providethe predetermined fifth output signal. Alternatively, or in addition,valve controller 26 may be configured to compare the third measure witha sixth pressure threshold (e.g. a low pressure threshold), or otherpressure threshold, programmed into and stored in valve controller 26,where valve controller 26 may be configured to provide a predeterminedsixth output signal if the third measure surpasses the sixth pressurethreshold. The predetermined fifth and sixth output signals may indicatea pressure event has occurred and/or other data or information relatedto the pressure event.

As discussed above, the HGP/LGP testing may be performed with one ormore pressure sensors. The numbering and positioning of the pressuresensors (e.g., first pressure sensor 42—upstream, second pressure sensor43—downstream, third pressure sensor 44—intermediate, etc.) is forillustrative purposes only. For example, there may be a single pressuresensor in valve assembly 10, where the single pressure sensor is locatedupstream of the valve port(s) 20, downstream of the valve port(s) 20 orintermediate the valve ports 20. Further, each pressure sensor 38, 42,43, 44 included in valve assembly 10 may be associated with one or morepressure threshold value and those one or more pressure threshold valuesmay be similar to or different from one or more pressure thresholdvalues associated with any other pressure sensor.

Valve controller 26 may include software to effect methods of operationdisclosed herein. In some illustrative instances, software filteringtechniques may be utilized to eliminate transient pressure readings fromcausing a false opening of a switch 69 in the limit string 67, forexample, a switch in series with safety switch 70, which may helpprevent nuisance valve port(s) 20 closures. Safety switch 70 may bewired in series between main valve switches 72, 74 and the limit string67, for example. In such a configuration, if valve controller 26 detectsa pressure event, valve controller 26 may initiate a series of actionsresulting in a switch 69 in the limit string 67 opening, which mayremove power from main valve switches 72, 74, resulting in valve ports20 closing. The software may help improve robustness of the system byallowing the software to be intelligent about when it monitors thesensor states and what action is taken in response.

As the functions of HGP/LGP switches may now be emulated by sensors andelectronics, and the output may no longer only be a simple “switch open”or “switch closed”, but rather, in addition or alternatively, an actualreadable pressure value or value related thereto, it may be advantageousto configure valve controller 26 to communicate this data to a remotedevice (e.g., a building automation system or system controller 50, anappliance controller 60, etc.) or display 52, 62. System display 52 orappliance display 62 may be configured to show threshold pressures alongwith actual sensed pressures during operation to show a user how muchmargin there is until a pressure event trip point. In addition, valvecontroller 26 may be configured to communicate to system controller 50or appliance controller 60 that a pressure event has occurred, which mayresult in an indicator being displayed on displays 52, 62. Suchcommunication may take place over a wired or wireless bus or link 100,where the bus may be configured to carry data to and from valve assembly10. In some cases, low and high pressure thresholds may be inputted byan operator of valve assembly 10 and may be downloaded or otherwiseprogrammed into valve controller 26.

Note, first, second, third, fourth, fifth and sixth pressure thresholdsand output signals are merely some illustrative examples, and there maybe any number of pressure thresholds and output signals with respect toeach provided pressure sensor 42, 43, 44 (or 38), as desired. Further,with respect to a first and second pressure threshold related to asingle valve port 20 and/or pressure sensor 42, 43, 44 (or 38), one ofthe first or second pressure threshold may relate to a high or lowpressure threshold and the other pressure threshold may relate to theother of the high and low pressure thresholds. In addition, each of theone or more first pressure sensors 42, each of the one or more secondpressure sensors 43 and each of the third pressure sensors 44,respectively, may include pressure sensors each having different or thesame pressure sub-ranges. For example, where two third pressure sensors44 are positioned downstream of the first valve port 20 a and upstreamof second valve port 20 b, one of the two third pressure sensors 44 mayhave a first pressure sensing sub-range over which it may sensepressures and the other of the two third pressure sensors 44 may have asecond pressure sensing sub-range over which it may sense pressures, butthis is not required.

Although valve controller 26 may be configured to provide theabove-mentioned first, second, third, fourth, fifth, and/or sixth outputsignals when the first, second, or third sensed measure related to eachvalve port 20 surpasses one of the pressure threshold stored in valvecontroller 26 to indicate a pressure event has occurred, valvecontroller 26 may be configured to not provide the predetermined first,second, third, fourth, fifth, or sixth output signal during at least onetime period, even if any of the first, second, or third measures surpassa respective pressure threshold. For example, valve controller 26 may beprogrammed to not provide the predetermined output signal where the onetime period is associated with a status of the first and/or second valveactuators 30 a, 30 b (e.g., at or around when the first and/or secondvalve actuator 30 a, 30 b are being actuated, etc.). Actuating the firstand/or second valve actuator 30 a, 30 b may cause pressure transients,which could result in false HGP or LGP events. In some, but not allcases, for example, microcontroller 36 may be taught to ignore sensedpressures when valve port(s) 20 is/are closed, as the outlet pressuremay be close to zero and likely below any threshold value and a sensedpressure in the intermediate volume 19 may be in a range from aroundzero to the inlet pressure.

Although typical safety valve assemblies may have sensed HGP downstreamof a second valve port 20 b and LGP upstream of a first valve port 20 a,utilizing sensors of pressure sensor assembly 24 may allow pressure tobe monitored at a single pressure sensor positioned at a single location(e.g. upstream of the first valve, intermediate the first and secondvalves, or downstream of the second valve) in or about valve assembly10. Further, the microcontroller 36 onboard the valve assembly 10 mayallow the valve controller 26 to assess when the combustion appliance ison and when it is off and in which state (e.g. open/closed) the valvesealing members 22 are positioned. Furthermore, it is possible toobserve with one or more pressure sensors both HGP and LGP statesupstream, downstream, and/or intermediate valve port(s) 20. Asdiscussed, a single pressure sensor may be located at any positionwithin or about valve assembly 10, such that the pressure sensor may bein fluid communication with fluid channel 18. A single pressure sensorconfiguration for detecting HGP and LGP may be facilitated by havingmicroprocessor 36 observing sensed data for both low and high pressureconditions simultaneously. In one example, a single pressure sensorintermediate the first valve port 20 a and the second valve port 20 b,may monitor for both HGP and LGP events in the gas stream provided tothe gas valve assembly 10. In the example, the single pressure sensorintermediate the first valve port 20 a and the second valve port 20 bmay monitor for both HGP and LGP events whenever at least the firstvalve port 20 a is open.

Valve Proving System Test

Valve controller 26 may be configured to perform an electronic valveproving system (VPS) test on valve assembly 10, where all orsubstantially all of the structure required for the VPS may beintegrated directly into valve assembly 10. When so provided, the directintegration may allow sensors and electronics needed for VPS testing toshare a common housing. Valve assembly 10 may be in communication withcombustion appliance controller 60 or other device, and may at leastpartially control a fuel flow to a combustion appliance through fluidchannel 18. Illustratively, the combustion appliance may cycle on andoff during a sequence of operational cycles, where at least some of theoperational cycles may include performing a VPS test prior to and/orafter igniting received fuel during the corresponding operational cycle.For example, VPS tests may be performed on each valve port 20 prior toigniting received fuel during a corresponding operational cycle, VPStests may be performed on each valve port 20 after a call for heat issatisfied (e.g., at the very end of an operational cycle), or a VPS testmay be performed on a first valve port 20 prior to igniting receivedfuel during a corresponding operational cycle and on a second valve port20 after a call for heat is satisfied. Due to the timing of the VPS testbefore and/or after operational cycles, or both, the test may beachieved in an amount of time consistent with the useful operation of anindividual appliance (e.g., a short amount of time of 10-15 seconds or5-30 seconds or a longer amount of time) depending on the inletpressure, size of the intermediate volume 19, volume of the appliancecombustion chamber, length of time of the appliance pre-purge cycle,firing rate of the appliance burner, the leakage threshold level, etc.The VPS test may be an automated process that occurs every, or at leastsome, operational cycle(s) (e.g., once the VPS test has been set up by afield installer or at the original equipment manufacturer, the testingmay not require the end user to participate in any way).

The structural set up of valve assembly 10 for a VPS test may includevalve controller 26 in communication with a pressure sensor 44 that maybe in fluid communication with intermediate volume 19 between two valveports (e.g., first valve port 20 a and second valve port 20 b, as seenin FIG. 8). Where valve controller 26 is in communication with pressuresensor 44, valve controller 26 may be configured to determine a measurerelated to a pressure change rate (e.g., pressure rise or pressure decayrate, or other measure) in intermediate volume 19 during each VPS testperformed as part of at least some of the operational cycles of thecombustion appliance, or at other times. Alternatively, or in addition,valve controller 26 may be in communication with one or more inletpressure sensor 42, outlet pressure sensor 43 or other pressure sensors(e.g., differential pressure sensor 38 and/or other sensors), wherepressure sensors 38, 42, 43 sense measures related to the pressureupstream of a first port 20 a and downstream of a second port 20 b,respectively, and communicate the sensed measures to valve controller26. Although pressure sensors downstream of the ports (e.g., pressuresensor(s) 43) may not be directly used to determine whether a valve isleaking, the downstream pressure sensor(s) 43 may continuously monitoroutlet pressure during leakage tests of the valves and, in some cases,may facilitate determining which valve is leaking if a valve leakage isdetected.

In some cases, utilizing an inlet pressure sensor 42 in addition to oras an alternative to pressure sensor 44 may allow controller 26 todetermine in real time which valve port 20 is leaking. By using pressuresensor 42 at the inlet, the inlet pressure may be known prior to a VPSsequence and controller 26 may be able to pre-determine thresholds forpressure rise and decay based on knowing the inlet pressure prior to theVPS sequence. Such pre-determination of the thresholds may allow sensedpressures to be compared to the thresholds at any time during the VPSsequence.

Valve controller 26 may include non-volatile memory 37 or other memorythat may include a first VPS threshold value (e.g., for comparing to apressure rise) and a second VPS threshold value (e.g., for comparing toa pressure decay) utilized in performing the VPS test. Alternatively, orin addition, the memory may be located at a position other than in valvecontroller 26, such that any remote memory may be in communication withvalve controller 26. Valve controller 26 may further be configured tocompare the determined measure related to a pressure change rate in theintermediate volume 19 to the first and/or second threshold value duringa first valve leakage test having a first duration, and/or comparing themeasure that is related to a pressure change rate in the intermediatevolume 19 to the third and/or fourth threshold value during a secondvalve leakage test having a second duration that is longer than thefirst duration. Illustratively, the first and/or second threshold valuesmay be utilized in a valve leakage test each time a combustion applianceor other device connected to valve assembly 10 opens one or more valveports 20, for example, in a VPS test or other test. The third and/orfourth threshold values may be utilized in a valve leakage test or othertest performed as scheduled maintenance while valve assembly 10 isoffline, at the time of commissioning of valve assembly 10, and/or atother preferred times.

The VPS test may be achieved by commanding valve actuators 30 to openand/or closed in a useful sequence. This sequence may be initializedand/or controlled through valve controller 26 and/or through thecombustion appliance controller 60. When the VPS sequence is initializedand controlled remotely (e.g., remote from valve controller 26) throughthe combustion appliance controller 60, the valve controller 26 may beconfigured to detect if the VPS test or another test is occurring bymonitoring gas valve assembly 10 and signals communicated to valveassembly 10. If the VPS test is to be controlled by the valve controller26, the set up of the VPS settings may occur at a display/user interface76 on board the valve itself or at a remote display (e.g., displays 52,62). If the VPS test is to be actuated or initiated at or throughcombustion appliance controller 60, the set up of the VPS settings mayoccur at a remote display (e.g., displays 52, 62). Valve controller 26may monitor valve actuators 30 a, 30 b, first control signal (MV1)controlling first valve actuator 30 a and second control signal (MV2)controlling second valve actuator 30 b, and/or the states of valve ports20 a, 20 b (e.g., by monitoring the output of position sensor(s) 48) toidentify if the VPS test is occurring. First and second control signals(MV1 and MV2) may be actuated by a combustion appliance controller 60 incommunication with valve assembly 10 or by a valve controller 26 or by afield tool in communication with valve controller 26 or any other toolor individual in communication with valve assembly 10. Although thefield tool and other tools are most often used for actuating first andsecond control signals (MV1 and MV2) in a valve leakage test, suchsimilar or different tools may be used to operate a VPS test or forsystem level diagnostics and/or troubleshooting by a trained appliancetechnician in the field.

In performing a VPS test, valve controller 26 may cause or identify thefollowing first predetermined sequence. The first valve actuator 30 amay close the first valve port 20 a (if not already closed). The secondvalve actuator 30 b may then open the second valve port 20 b (if notalready opened) to depressurize the intermediate volume 19 between thefirst valve port 20 a and the second valve port 20 b. The second valveactuator 30 b may then close the second valve port 20 b to seal thedepressurized intermediate volume 19.

Valve controller 26 may cause or identify this first predeterminedsequence as a first sub-test of a VPS test, and valve controller 26 maybe configured to compare a measure that is related to the pressurechange rate in intermediate volume 19 to a first VPS sub-test thresholdvalue prior to, during, or after a first sub-set VPS duration. After orwhile comparing the measure related to the pressure change rate inintermediate volume 19 to the first sub-test threshold value, valvecontroller 26 may output a signal if the measure meets and/or exceedsthe first sub-test threshold value. Valve controller 26 may beconfigured to output the signal over the communication bus 100 or usinga simple pair of contacts (e.g., relay contacts that close when ameasured pressure surpasses a threshold pressure value) at or incommunication with appliance controller 60, one or more of a localdisplay, a remote device 50, 60 and/or a remote display 52, 62 of theremote device(s) 50, 60. The first sub-test of the VPS test may beconfigured to at least detect a leaking first valve port 20 a. Theoutputted signal may indicate, or may cause to be indicated, a valveleakage within valve assembly 10 and/or a measure of the magnitude ofthe valve leakage.

In addition to identifying the first sub-test of a VPS test, valvecontroller 26 may cause or identify the following second predeterminedsequence. The second valve actuator 30 b may close the second valve port20 b (if not already closed). The first valve actuator 30 a may thenopen the first valve port 20 a (if not already opened) to pressurize theintermediate volume 19 between the first valve port 20 a and the secondvalve port 20 b. The first valve actuator 30 a may then close the firstvalve port 20 a to seal the pressurized intermediate volume 19.

Valve controller 26 may cause or identify this second predeterminedsequence as a second sub-test of a VPS test, and valve controller 26 maybe configured to compare a measure that is related to the pressurechange rate in intermediate volume 19 to a second VPS sub-test thresholdvalue prior to, during, or after a second sub-set VPS duration. After orwhile comparing the measure related to the pressure change rate inintermediate volume 19 to the second sub-test threshold value, valvecontroller 26 may output a signal if the measure meets and/or exceedsthe second sub-test threshold value. Valve controller 26 may beconfigured to output the signal to one or more of a local display, aremote device 50, 60 and/or a remote display 52, 62 of the remotedevice(s) 50, 60. The second sub-test of the VPS test may be configuredto at least detect a leaking second valve port 20 b. The outputtedsignal may indicate, or may cause to be indicated, a valve leakagewithin valve assembly 10 and/or a measure of the magnitude of the valveleakage. Further, first VPS sub-test and second VPS sub-test of the VPStest may be performed in any order, as desired.

The first and second VPS sub-test threshold values may be programmedinto valve controller 26, and the first and second VPS sub-testthreshold values may be different or substantially the same value.Alternatively, or in addition, valve controller 26 may be configured tocalculate the first and second VPS sub-test threshold values based onone or more parameters and, in some instances, the valve controller 26may be configured to store the first and second VPS sub-test thresholdvalues. The one or more parameters that valve controller 26 may considerif it is determining a VPS sub-test threshold value include, but are notlimited to, a sensed pressure, a sensed temperature, max flow rate ofthe system, a number of ON-OFF cycles operated up to a point in time,volume of flow channel 18, altitude of valve assembly 10, barometricpressure, absolute pressure, gas type (e.g., density), ANSIrequirements, EN requirements, other agency requirements, an allowed VPStest duration, and how small of a leak is to be detected, etc. Further,in the event more than two sub-tests are performed as part of the VPStest, there may be more threshold values than the first and second VPSsub-test threshold values, if desired.

In an illustrative operation, a VPS test may be performed on a valveassembly 10 that is coupled to a non-switched gas source, or other gassource, that is under a positive pressure during the VPS test to testgas valve assembly 10 for leaks.

A similar VPS test performed on valve assembly 10 may include openingone of the first and second valve port 20 a, 20 b with the other of thefirst and second valve ports 20 a, 20 b remaining or being closed. Afteropening one of the first and second valve ports 20 a, 20 b, closing theopened valve port such that both valve ports 20 a, 20 b are closed suchthat a first initial gas pressure may be present in intermediate volume19. An intermediate pressure sensor 44 may continuously ordiscontinuously sense a pressure in intermediate volume 19, includingthe first initial pressure therein, and send the sensed pressures tovalve controller 26. The initial pressure in intermediate volume 19 maybe sensed at any time, for example, the initial pressure may be sensedafter opening one of the valve ports 20 a, 20 b and before closing thatopened valve port 20 a, 20 b. Valve controller 26 may monitor (e.g.,continuously or discontinuously), over time, the pressure inintermediate volume 19 and determine a first measure that is related toa pressure change rate within intermediate volume 19 while both valveports 20 a, 20 b are in a closed position. After determining the firstmeasure that is related to a pressure change rate within intermediatevolume 19, valve controller 26 may compare the determined first measurerelated to a pressure change rate in the intermediate volume 19 to afirst threshold value stored in valve controller 26. Valve controller 26may then output to a display and/or remote device 50, 60 or other devicean output signal that is related to the first measure related to thepressure change rate (e.g., a determined pressure change in intermediatevolume 19, or other determined measure), where outputting the outputsignal may also include storing the determined first measure related tothe pressure change rate in non-volatile memory 37 on valve controller26. Optionally, valve controller 26 may output the output signal if thedetermined first measure meets and/or exceeds the first threshold value.The output signal, however, may convey any information, as desired. Forexample, the output signal may convey information related to when (e.g.time stamp) the determined measure that is related to the pressurechange rate meets and/or exceeds a threshold value, or other informationrelated to or not related to the pressure in intermediate volume 19. Inan alternative, or in addition to providing the output signal, a visualand/or audible indicator may be provided to indicate if valve assembly10 passed or failed the VPS test.

In addition, first and/or second valve port 20 a, 20 b may bemanipulated such that a second initial gas pressure may be present inthe intermediate volume 19 while the first and second valve ports 20 a,20 b are in the closed position. For example, second valve port 20 b maybe closed, then the first valve port 20 a may be opened to pressurizeintermediate volume 19 and then closed to seal in the second initialpressure. The second initial pressure may be substantially differentthan the first initial gas pressure, as the first initial pressure maybe associated with a depressurized state of intermediate volume 19 andthe second initial pressure may be associated with a pressurized stateof intermediate volume 19, for example. Similar to above, intermediatepressure sensor 44 may sense pressure within intermediate volume 19 andcommunicate the sensed pressure and measures related to the sensedpressures to valve controller 26. Valve controller 26 may monitor (e.g.,continuously or discontinuously), over time, the pressure inintermediate volume 19 and determine a second measure that is related toa pressure change rate within intermediate volume 19 while both valveports 20 a, 20 b are in the closed position. After determining thesecond measure that is related to a pressure change rate withinintermediate volume 19, valve controller 26 may compare the determinedsecond measure related to a pressure change rate in the intermediatevolume 19 to a second threshold value stored in valve controller 26.Valve controller 26 may then output to a display and/or remote device50, 60 or other device an output signal that is related to the secondmeasure related to a pressure change rate, where outputting the outputsignal may also include storing the determined second measure related tothe pressure change rate in non-volatile memory 37 on valve controller26. Optionally, valve controller 26 may output the output signal or adifferent output signal if the determined second measure meets and/orexceeds the second threshold value. The output signal, however, mayconvey any information and the outputted signals may be outputted in anysituation. Further, the output signal may be configured to provide, orcause to be provided, a visual and/or audible indicator to indicate ifvalve assembly 10 passed and/or failed the VPS test.

The steps of the illustrative VPS test may be performed once such aswhen the gas valve assembly 10 is installed or during routinemaintenance, and/or the steps may be repeated during each combustioncycle of a combustion appliance. In either case, the valve controller 26or other device, or even a user, may identify a trend in the storeddetermined measures related to the pressure change rate or in other datasensed, calculated and/or stored during the valve leakage tests. Adetermined trend may be used for any of many purposes, for example, atrend may be used to predict when the valve will require replacementand/or servicing, and/or to make other predictions. Further, a VPS testand/or leakage test may be initiated and/or operated dependent on orindependent of an attached device (e.g., a combustion appliancecontroller 60). In such an instance, valve controller 26 may beconfigured to initiate and operate a VPS test and/or leakage testindependent of an attached device and may be configured to disable aheat call or other signal to and/or from an attached device, whenappropriate.

Valve Leakage Test (VLT)

Valve controller 26 may be configured to perform a Valve Leakage (VL)Test on valve assembly 10. Valve controller 26 may be manuallyinitialized by a field service technician or other user at either alocal display on the valve assembly 10 (e.g., when valve controller 26controls the operation of the VL test) or at a remote display 52, 62(e.g., when either the valve controller 26 controls the operation of theVL test or when the VL test is remotely controlled). Similar to the setup for a VPS test, the structural set up of valve assembly 10 for a VLtest may include valve controller 26 in communication with a pressuresensor 44 that may be in fluid communication with intermediate volume 19between two valve ports 20 (e.g., first valve port 20 a and second valveport 20 b), as seen in FIG. 8. Where valve controller 26 is incommunication with pressure sensor 44, valve controller 26 may beconfigured to determine a measure related to a pressure change rate(e.g., pressure rise or decay rate, or other measure) in intermediatevolume 19 when both the first valve port 20 a and second valve port 20 bare closed.

The VL test may be performed in the same manner as the VPS testdiscussed above. However, in the VL test, the test duration may belonger (e.g., one minute, two minutes, several minutes, or other timeperiod that may possibly be longer than a typical length of time it maytake to run a VPS test) during which time a combustion appliance may beoffline, thereby allowing smaller leaks to be detected. Also, thethresholds values used during the VL test may be different from thoseused in the VPS test. Also, the VL test may be performed less frequentlythan the VPS test. For example, the VL test may be performed once a yearor during routine maintenance, and not during every combustion cycle.

In some cases, valve controller 26 may be configured to initiate a VLtest. In some instances, the valve controller 26 may be configured todetect if a VPS test or a longer, Valve Leakage (VL) test, is occurringby monitoring gas valve assembly 10 and signals communicated to valveassembly 10. For example, valve controller 26 may monitor valveactuators 30 a, 30 b, first control signal (MV1) controlling first valveactuator 30 a and/or second control signal (MV2) controlling secondvalve actuator 30 b, and/or the states of valve ports 20 a, 20 b toidentify if a VPS test or a longer VL test is occurring. In some cases,first and second control signals (MV1 and MV2) may be controlled by acombustions appliance in communication with valve assembly 10 or a fieldtool in communication with valve assembly 10 or any other tool orindividual in communication with valve assembly 10. If a VL test isdetected, valve controller 26 may automatically apply thresholdsassociated with the longer VL test rather than thresholds of the shorterVPS test. The valve controller 26 may revert back, automatically orotherwise, to using VPS thresholds after the longer VL test has beencompleted, if desired.

When valve assembly 10 may be disconnected from a combustion appliancecontroller 60 and connected to a field tool to effect the VL test withVL thresholds, it is contemplated that when combustion appliancecontroller 60 is reconnected with valve assembly 10, previous combustionappliance-valve assembly thresholds/conditions (e.g., VPS thresholds)may be automatically reset, as valve controller 26 and device controller60 may automatically detect the reconnection.

Those skilled in the art will recognize that the present disclosure maybe manifested in a variety of forms other than the specific embodimentsdescribed and contemplated herein. Accordingly, departure in form anddetail may be made without departing from the scope and spirit of thepresent disclosure as described in the appended claims.

What is claimed is:
 1. A valve assembly for controlling fuel flow to acombustion appliance, the combustion appliance cycling on and off duringa sequence of operational cycles, at least some of the operationalcycles of the combustion appliance each performing a valve proving testprior to and/or after igniting the fuel during the operational cycle,the valve assembly comprising: a valve body having an inlet port and anoutlet port, with a fluid path extending between the inlet port and theoutlet port; a first valve situated in the fluid path between the inletport and the outlet port; a second valve situated in the fluid pathbetween the inlet port and the outlet port downstream of the firstvalve, with an intermediate volume between the first valve and thesecond valve defined by the valve body; a first valve actuator, securedrelative to the valve body, for selectively moving the first valvebetween a closed position, which closes the fluid path between the inletport and the outlet port, and an open position; a second valve actuator,secured relative to the valve body, for selectively moving the secondvalve between a closed position, which closes the fluid path between theinlet port and the outlet port, and an open position; a pressure sensorin fluid communication with the intermediate volume between the firstvalve and the second valve for sensing a measure that is related to apressure in the intermediate volume; a controller, secured relative tothe valve body and in communication with the pressure sensor, thecontroller configured to determine a measure that is related to apressure in the intermediate volume during each valve proving test thatis performed as part of at least some of the operational cycles of thecombustion appliance; wherein the controller is configured to comparethe measure that is related to the pressure in the intermediate volumeto a first sub-test threshold value during a first sub-test of the valveproving test; and the controller is further configured to compare themeasure that is related to the pressure in the intermediate volume to asecond sub-test threshold value that is a different value than the firstsub-test threshold value during a second sub-test of the valve provingtest.
 2. The valve assembly of claim 1, further comprising: an inletpressure sensor positioned upstream of the first valve for sensing ameasure related to the pressure upstream of the first valve; and thecontroller is coupled to the inlet pressure sensor and receives themeasure related to the pressure upstream of the first valve.
 3. Thevalve assembly of claim 2, further comprising: an outlet pressure sensorpositioned downstream of the second valve for sensing a measure relatedto the pressure downstream of the second valve; and the controller iscoupled to the outlet pressure sensor and receives the measure relatedto the pressure downstream of the second valve.
 4. The valve assembly ofclaim 1, further comprising: an outlet pressure sensor positioneddownstream of the second valve for sensing a measure related to thepressure downstream of the second valve; and the controller is coupledto the outlet pressure sensor and receives the measure related to thepressure downstream of the second valve.
 5. The valve assembly of claim1, wherein the controller is configured to identify the first sub-testof the valve proving test when the first valve actuator closes the firstvalve, and the second valve actuator opens the second valve todepressurize the intermediate volume and then closes the second valve.6. The valve assembly of claim 5, wherein the controller outputs asignal if the measure that is related to the pressure in theintermediate volume during the first sub-test meets and/or exceeds thefirst sub-test threshold value.
 7. The valve assembly of claim 6,wherein the controller is configured to identify the second sub-test ofthe valve proving test when the second valve actuator closes the secondvalve, and the first valve actuator opens the first valve to pressurizethe intermediate volume and then closes the first valve.
 8. The valveassembly of claim 7, wherein the controller outputs a signal if themeasure that is related to the pressure in the intermediate volumeduring the second sub-test meets and/or exceeds the second sub-testthreshold value.
 9. The valve assembly of claim 1, wherein the firstvalve actuator is controlled by a first control signal (MV1) and thesecond valve actuator is controlled by a second control signal (MV2),and wherein the controller is configured to detect if the valve provingtest is occurring by detecting a predetermined sequence of the firstcontrol signal and the second control signal.
 10. The valve assembly ofclaim 1, wherein: the first valve actuator is controlled by a firstcontrol signal (MV1); the second valve actuator is controlled by asecond control signal (MV2); the controller is configured to detect ifthe first sub-test of the valve proving test is occurring by detecting afirst predetermined sequence of the first control signal and the secondcontrol signal; the controller is configured to detect if the secondsub-test of the valve proving test is occurring by detecting a secondpredetermined sequence of the first control signal and the secondcontrol signal; the controller is configured to compare the measure thatis related to the pressure in the intermediate volume against the firstsub-test threshold value if the controller detects the first sub-test ofthe valve proving test; and the controller is configured to compare themeasure that is related to the pressure in the intermediate volumeagainst the second sub-test threshold value if the controller detectsthe second sub-test of the valve proving test.
 11. The valve assembly ofclaim 1, further comprising a temperature sensor for sensing a measurethat is related to the temperature of the fluid in the intermediatevolume, wherein the controller receives the measure that is related tothe temperature of the fluid in the intermediate volume.
 12. The valveassembly of claim 1, wherein the controller calculates the firstsub-test threshold value andlor the second sub-test threshold valuebased on one or more parameters.
 13. The valve assembly of claim 12,wherein the one or more parameters are selected from a sensed pressure,a sensed temperature, and a test duration.
 14. A method of testing a gasvalve assembly for leaks, the method comprising: performing a valveproving test on the gas valve assembly, the gas valve assembly includinga first valve, a second valve downstream of the first valve, a pressuresensor, and a controller, where the pressure sensor is positioned tosense a measure that is related to a pressure in an intermediate volumebetween the first valve and the second valve; closing the first valve;opening the second valve to depressurize the intermediate volume;closing the second valve; determining with the controller a firstmeasure that is related to a pressure in the intermediate volume;comparing with the controller the first measure that is related to thepressure in the intermediate volume to a first threshold value; closingthe second valve; opening the first valve to pressurize the intermediatevolume; closing the first valve; determining a second measure that isrelated to the pressure in the intermediate volume; comparing the secondmeasure that is related to the pressure in the intermediate volume to asecond threshold value, wherein the second threshold value is differentfrom the first threshold value; and outputting a signal if the firstmeasure that is related to the pressure in the intermediate volumereaches and/or exceeds the first threshold value and/or if the secondmeasure that is related to the pressure in the intermediate volumereaches and/or falls below the second threshold value.
 15. A method ofperforming a valve proving test of a gas valve assembly that is fluidlycoupled to a gas source that provides a positive gas pressure to the gasvalve assembly during the valve leakage test, the gas valve assemblyhaving a valve body, a first valve, a second valve downstream of thefirst valve, a pressure sensor, and a valve controller coupled to thevalve body and in electronic communication with the pressure sensor,where the pressure sensor is positioned to sense a measure that isrelated to a pressure in an intermediate volume between the first valveand the second valve, the method comprising: opening the first valvewith the second valve closed; closing the first valve; with both thefirst valve and the second valve in the closed position, sensing a firstinitial pressure in the intermediate volume between the first valve andthe second valve using the pressure sensor; with both the first valveand the second valve remaining in the closed position, monitoring overtime the pressure in the intermediate volume between the first valve andthe second valve using the pressure sensor, and determining a firstpressure change rate value; storing a measure related to the firstpressure change rate value in a memory; opening the second valve withthe first valve closed; closing the second valve; with both the firstvalve and the second valve in the closed position, sensing a secondinitial pressure in the intermediate volume between the first valve andthe second valve using the pressure sensor; with both the first valveand the second valve remaining in the closed position, monitoring overtime the pressure in the intermediate volume between the first valve andthe second valve using the pressure sensor, and determining a secondpressure change rate value; and storing a measure related to the secondpressure change rate value in the memory.
 16. The method of claim 15,further comprising: outputting an output signal that conveys when thefirst pressure change rate value meets and/or exceeds a first thresholdvalue.
 17. The method of claim 15, wherein the measure related to thefirst pressure change rate value and the measure related to the secondpressure change rate value are stored in a non-volatile memory.
 18. Themethod of claim 17, further comprising identifying a trend in themeasure related to the first pressure change rate value and/or themeasure related to the second pressure change rate value over time. 19.The method of claim 18, further comprising providing a visual and/oraudible indicator to indicate if the valve assembly passed and/or failedthe valve proving test based at least in part on the measure related tothe first pressure change rate value and the measure related to thesecond pressure change rate value stored in a non-volatile memory.